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Commit 5e1a87fb authored by peastman's avatar peastman
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Merge pull request #1142 from peastman/tests 

Refactored test cases
parents b11af401 cece0cdb
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tests/TestHarmonicBondForce.h 0 → 100644
View file @ 5e1a87fb
/* -------------------------------------------------------------------------- *
* OpenMM *
* -------------------------------------------------------------------------- *
* This is part of the OpenMM molecular simulation toolkit originating from *
* Simbios, the NIH National Center for Physics-Based Simulation of *
* Biological Structures at Stanford, funded under the NIH Roadmap for *
* Medical Research, grant U54 GM072970. See https://simtk.org. *
* *
* Portions copyright (c) 2008-2015 Stanford University and the Authors. *
* Authors: Peter Eastman *
* Contributors: *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* copy of this software and associated documentation files (the "Software"), *
* to deal in the Software without restriction, including without limitation *
* the rights to use, copy, modify, merge, publish, distribute, sublicense, *
* and/or sell copies of the Software, and to permit persons to whom the *
* Software is furnished to do so, subject to the following conditions: *
* *
* The above copyright notice and this permission notice shall be included in *
* all copies or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
* THE AUTHORS, CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE *
* USE OR OTHER DEALINGS IN THE SOFTWARE. *
* -------------------------------------------------------------------------- */
#include "openmm/internal/AssertionUtilities.h"
#include "openmm/Context.h"
#include "openmm/HarmonicBondForce.h"
#include "openmm/System.h"
#include "openmm/VerletIntegrator.h"
#include <iostream>
#include <vector>
using namespace OpenMM;
using namespace std;
const double TOL = 1e-5;
void testBonds() {
System system;
system.addParticle(1.0);
system.addParticle(1.0);
system.addParticle(1.0);
VerletIntegrator integrator(0.01);
HarmonicBondForce* forceField = new HarmonicBondForce();
forceField->addBond(0, 1, 1.5, 0.8);
forceField->addBond(1, 2, 1.2, 0.7);
system.addForce(forceField);
Context context(system, integrator, platform);
vector<Vec3> positions(3);
positions[0] = Vec3(0, 2, 0);
positions[1] = Vec3(0, 0, 0);
positions[2] = Vec3(1, 0, 0);
context.setPositions(positions);
State state = context.getState(State::Forces | State::Energy);
{
const vector<Vec3>& forces = state.getForces();
ASSERT_EQUAL_VEC(Vec3(0, -0.8*0.5, 0), forces[0], TOL);
ASSERT_EQUAL_VEC(Vec3(0.7*0.2, 0, 0), forces[2], TOL);
ASSERT_EQUAL_VEC(Vec3(-forces[0][0]-forces[2][0], -forces[0][1]-forces[2][1], -forces[0][2]-forces[2][2]), forces[1], TOL);
ASSERT_EQUAL_TOL(0.5*0.8*0.5*0.5 + 0.5*0.7*0.2*0.2, state.getPotentialEnergy(), TOL);
}
// Try changing the bond parameters and make sure it's still correct.
forceField->setBondParameters(0, 0, 1, 1.6, 0.9);
forceField->setBondParameters(1, 1, 2, 1.3, 0.8);
forceField->updateParametersInContext(context);
state = context.getState(State::Forces | State::Energy);
{
const vector<Vec3>& forces = state.getForces();
ASSERT_EQUAL_VEC(Vec3(0, -0.9*0.4, 0), forces[0], TOL);
ASSERT_EQUAL_VEC(Vec3(0.8*0.3, 0, 0), forces[2], TOL);
ASSERT_EQUAL_VEC(Vec3(-forces[0][0]-forces[2][0], -forces[0][1]-forces[2][1], -forces[0][2]-forces[2][2]), forces[1], TOL);
ASSERT_EQUAL_TOL(0.5*0.9*0.4*0.4 + 0.5*0.8*0.3*0.3, state.getPotentialEnergy(), TOL);
}
}
void runPlatformTests();
int main(int argc, char* argv[]) {
try {
initializeTests(argc, argv);
testBonds();
runPlatformTests();
}
catch(const exception& e) {
cout << "exception: " << e.what() << endl;
return 1;
}
cout << "Done" << endl;
return 0;
}
tests/TestLangevinIntegrator.h 0 → 100644
View file @ 5e1a87fb
/* -------------------------------------------------------------------------- *
* OpenMM *
* -------------------------------------------------------------------------- *
* This is part of the OpenMM molecular simulation toolkit originating from *
* Simbios, the NIH National Center for Physics-Based Simulation of *
* Biological Structures at Stanford, funded under the NIH Roadmap for *
* Medical Research, grant U54 GM072970. See https://simtk.org. *
* *
* Portions copyright (c) 2008-2015 Stanford University and the Authors. *
* Authors: Peter Eastman *
* Contributors: *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* copy of this software and associated documentation files (the "Software"), *
* to deal in the Software without restriction, including without limitation *
* the rights to use, copy, modify, merge, publish, distribute, sublicense, *
* and/or sell copies of the Software, and to permit persons to whom the *
* Software is furnished to do so, subject to the following conditions: *
* *
* The above copyright notice and this permission notice shall be included in *
* all copies or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
* THE AUTHORS, CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE *
* USE OR OTHER DEALINGS IN THE SOFTWARE. *
* -------------------------------------------------------------------------- */
#include "openmm/internal/AssertionUtilities.h"
#include "openmm/Context.h"
#include "openmm/HarmonicBondForce.h"
#include "openmm/NonbondedForce.h"
#include "openmm/System.h"
#include "openmm/LangevinIntegrator.h"
#include "SimTKOpenMMRealType.h"
#include "sfmt/SFMT.h"
#include <iostream>
#include <vector>
using namespace OpenMM;
using namespace std;
const double TOL = 1e-5;
void testSingleBond() {
System system;
system.addParticle(2.0);
system.addParticle(2.0);
LangevinIntegrator integrator(0, 0.1, 0.01);
HarmonicBondForce* forceField = new HarmonicBondForce();
forceField->addBond(0, 1, 1.5, 1);
system.addForce(forceField);
Context context(system, integrator, platform);
vector<Vec3> positions(2);
positions[0] = Vec3(-1, 0, 0);
positions[1] = Vec3(1, 0, 0);
context.setPositions(positions);
// This is simply a damped harmonic oscillator, so compare it to the analytical solution.
double freq = std::sqrt(1-0.05*0.05);
for (int i = 0; i < 1000; ++i) {
State state = context.getState(State::Positions | State::Velocities);
double time = state.getTime();
double expectedDist = 1.5+0.5*std::exp(-0.05*time)*std::cos(freq*time);
ASSERT_EQUAL_VEC(Vec3(-0.5*expectedDist, 0, 0), state.getPositions()[0], 0.02);
ASSERT_EQUAL_VEC(Vec3(0.5*expectedDist, 0, 0), state.getPositions()[1], 0.02);
double expectedSpeed = -0.5*std::exp(-0.05*time)*(0.05*std::cos(freq*time)+freq*std::sin(freq*time));
ASSERT_EQUAL_VEC(Vec3(-0.5*expectedSpeed, 0, 0), state.getVelocities()[0], 0.02);
ASSERT_EQUAL_VEC(Vec3(0.5*expectedSpeed, 0, 0), state.getVelocities()[1], 0.02);
integrator.step(1);
}
// Not set the friction to a tiny value and see if it conserves energy.
integrator.setFriction(5e-5);
context.setPositions(positions);
State state = context.getState(State::Energy);
double initialEnergy = state.getKineticEnergy()+state.getPotentialEnergy();
for (int i = 0; i < 1000; ++i) {
state = context.getState(State::Energy);
double energy = state.getKineticEnergy()+state.getPotentialEnergy();
ASSERT_EQUAL_TOL(initialEnergy, energy, 0.01);
integrator.step(1);
}
}
void testTemperature() {
const int numParticles = 8;
const double temp = 100.0;
System system;
LangevinIntegrator integrator(temp, 2.0, 0.01);
NonbondedForce* forceField = new NonbondedForce();
for (int i = 0; i < numParticles; ++i) {
system.addParticle(2.0);
forceField->addParticle((i%2 == 0 ? 1.0 : -1.0), 1.0, 5.0);
}
system.addForce(forceField);
Context context(system, integrator, platform);
vector<Vec3> positions(numParticles);
for (int i = 0; i < numParticles; ++i)
positions[i] = Vec3((i%2 == 0 ? 2 : -2), (i%4 < 2 ? 2 : -2), (i < 4 ? 2 : -2));
context.setPositions(positions);
// Let it equilibrate.
integrator.step(10000);
// Now run it for a while and see if the temperature is correct.
double ke = 0.0;
for (int i = 0; i < 10000; ++i) {
State state = context.getState(State::Energy);
ke += state.getKineticEnergy();
integrator.step(1);
}
ke /= 10000;
double expected = 0.5*numParticles*3*BOLTZ*temp;
ASSERT_USUALLY_EQUAL_TOL(expected, ke, 6/std::sqrt(10000.0));
}
void testConstraints() {
const int numParticles = 8;
const int numConstraints = 5;
const double temp = 100.0;
System system;
LangevinIntegrator integrator(temp, 2.0, 0.01);
integrator.setConstraintTolerance(1e-5);
NonbondedForce* forceField = new NonbondedForce();
for (int i = 0; i < numParticles; ++i) {
system.addParticle(10.0);
forceField->addParticle((i%2 == 0 ? 0.2 : -0.2), 0.5, 5.0);
}
system.addConstraint(0, 1, 1.0);
system.addConstraint(1, 2, 1.0);
system.addConstraint(2, 3, 1.0);
system.addConstraint(4, 5, 1.0);
system.addConstraint(6, 7, 1.0);
system.addForce(forceField);
Context context(system, integrator, platform);
vector<Vec3> positions(numParticles);
vector<Vec3> velocities(numParticles);
OpenMM_SFMT::SFMT sfmt;
init_gen_rand(0, sfmt);
for (int i = 0; i < numParticles; ++i) {
positions[i] = Vec3(i/2, (i+1)/2, 0);
velocities[i] = Vec3(genrand_real2(sfmt)-0.5, genrand_real2(sfmt)-0.5, genrand_real2(sfmt)-0.5);
}
context.setPositions(positions);
context.setVelocities(velocities);
// Simulate it and see whether the constraints remain satisfied.
for (int i = 0; i < 1000; ++i) {
State state = context.getState(State::Positions);
for (int j = 0; j < numConstraints; ++j) {
int particle1, particle2;
double distance;
system.getConstraintParameters(j, particle1, particle2, distance);
Vec3 p1 = state.getPositions()[particle1];
Vec3 p2 = state.getPositions()[particle2];
double dist = std::sqrt((p1[0]-p2[0])*(p1[0]-p2[0])+(p1[1]-p2[1])*(p1[1]-p2[1])+(p1[2]-p2[2])*(p1[2]-p2[2]));
ASSERT_EQUAL_TOL(distance, dist, 1e-4);
}
integrator.step(1);
}
}
void testConstrainedMasslessParticles() {
System system;
system.addParticle(0.0);
system.addParticle(1.0);
system.addConstraint(0, 1, 1.5);
vector<Vec3> positions(2);
positions[0] = Vec3(-1, 0, 0);
positions[1] = Vec3(1, 0, 0);
LangevinIntegrator integrator(300.0, 2.0, 0.01);
bool failed = false;
try {
// This should throw an exception.
Context context(system, integrator, platform);
}
catch (exception& ex) {
failed = true;
}
ASSERT(failed);
// Now make both particles massless, which should work.
system.setParticleMass(1, 0.0);
Context context(system, integrator, platform);
context.setPositions(positions);
context.setVelocitiesToTemperature(300.0);
integrator.step(1);
State state = context.getState(State::Velocities);
ASSERT_EQUAL(0.0, state.getVelocities()[0][0]);
}
void testRandomSeed() {
const int numParticles = 8;
const double temp = 100.0;
System system;
LangevinIntegrator integrator(temp, 2.0, 0.01);
NonbondedForce* forceField = new NonbondedForce();
for (int i = 0; i < numParticles; ++i) {
system.addParticle(2.0);
forceField->addParticle((i%2 == 0 ? 1.0 : -1.0), 1.0, 5.0);
}
system.addForce(forceField);
vector<Vec3> positions(numParticles);
vector<Vec3> velocities(numParticles);
for (int i = 0; i < numParticles; ++i) {
positions[i] = Vec3((i%2 == 0 ? 2 : -2), (i%4 < 2 ? 2 : -2), (i < 4 ? 2 : -2));
velocities[i] = Vec3(0, 0, 0);
}
// Try twice with the same random seed.
integrator.setRandomNumberSeed(5);
Context context(system, integrator, platform);
context.setPositions(positions);
context.setVelocities(velocities);
integrator.step(10);
State state1 = context.getState(State::Positions);
context.reinitialize();
context.setPositions(positions);
context.setVelocities(velocities);
integrator.step(10);
State state2 = context.getState(State::Positions);
// Try twice with a different random seed.
integrator.setRandomNumberSeed(10);
context.reinitialize();
context.setPositions(positions);
context.setVelocities(velocities);
integrator.step(10);
State state3 = context.getState(State::Positions);
context.reinitialize();
context.setPositions(positions);
context.setVelocities(velocities);
integrator.step(10);
State state4 = context.getState(State::Positions);
// Compare the results.
for (int i = 0; i < numParticles; i++) {
for (int j = 0; j < 3; j++) {
ASSERT(state1.getPositions()[i][j] == state2.getPositions()[i][j]);
ASSERT(state3.getPositions()[i][j] == state4.getPositions()[i][j]);
ASSERT(state1.getPositions()[i][j] != state3.getPositions()[i][j]);
}
}
}
void runPlatformTests();
int main(int argc, char* argv[]) {
try {
initializeTests(argc, argv);
testSingleBond();
testTemperature();
testConstraints();
testConstrainedMasslessParticles();
testRandomSeed();
runPlatformTests();
}
catch(const exception& e) {
cout << "exception: " << e.what() << endl;
return 1;
}
cout << "Done" << endl;
return 0;
}
tests/TestLocalEnergyMinimizer.h 0 → 100644
View file @ 5e1a87fb
/* -------------------------------------------------------------------------- *
* OpenMM *
* -------------------------------------------------------------------------- *
* This is part of the OpenMM molecular simulation toolkit originating from *
* Simbios, the NIH National Center for Physics-Based Simulation of *
* Biological Structures at Stanford, funded under the NIH Roadmap for *
* Medical Research, grant U54 GM072970. See https://simtk.org. *
* *
* Portions copyright (c) 2010-2015 Stanford University and the Authors. *
* Authors: Peter Eastman *
* Contributors: *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* copy of this software and associated documentation files (the "Software"), *
* to deal in the Software without restriction, including without limitation *
* the rights to use, copy, modify, merge, publish, distribute, sublicense, *
* and/or sell copies of the Software, and to permit persons to whom the *
* Software is furnished to do so, subject to the following conditions: *
* *
* The above copyright notice and this permission notice shall be included in *
* all copies or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
* THE AUTHORS, CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE *
* USE OR OTHER DEALINGS IN THE SOFTWARE. *
* -------------------------------------------------------------------------- */
#include "openmm/internal/AssertionUtilities.h"
#include "openmm/Context.h"
#include "openmm/HarmonicBondForce.h"
#include "openmm/LocalEnergyMinimizer.h"
#include "openmm/NonbondedForce.h"
#include "openmm/VerletIntegrator.h"
#include "openmm/VirtualSite.h"
#include "sfmt/SFMT.h"
#include <iostream>
#include <vector>
using namespace OpenMM;
using namespace std;
void testHarmonicBonds() {
const int numParticles = 10;
System system;
HarmonicBondForce* bonds = new HarmonicBondForce();
system.addForce(bonds);
// Create a chain of particles connected by harmonic bonds.
vector<Vec3> positions(numParticles);
for (int i = 0; i < numParticles; i++) {
system.addParticle(1.0);
positions[i] = Vec3(i, 0, 0);
if (i > 0)
bonds->addBond(i-1, i, 1+0.1*i, 1);
}
// Minimize it and check that all bonds are at their equilibrium distances.
VerletIntegrator integrator(0.01);
Context context(system, integrator, platform);
context.setPositions(positions);
LocalEnergyMinimizer::minimize(context, 1e-5);
State state = context.getState(State::Positions);
for (int i = 1; i < numParticles; i++) {
Vec3 delta = state.getPositions()[i]-state.getPositions()[i-1];
ASSERT_EQUAL_TOL(1+0.1*i, sqrt(delta.dot(delta)), 1e-4);
}
}
void testLargeSystem() {
const int numMolecules = 25;
const int numParticles = numMolecules*2;
const double cutoff = 2.0;
const double boxSize = 4.0;
const double tolerance = 10;
System system;
system.setDefaultPeriodicBoxVectors(Vec3(boxSize, 0, 0), Vec3(0, boxSize, 0), Vec3(0, 0, boxSize));
NonbondedForce* nonbonded = new NonbondedForce();
nonbonded->setCutoffDistance(cutoff);
nonbonded->setNonbondedMethod(NonbondedForce::CutoffPeriodic);
system.addForce(nonbonded);
// Create a cloud of molecules.
OpenMM_SFMT::SFMT sfmt;
init_gen_rand(0, sfmt);
vector<Vec3> positions(numParticles);
for (int i = 0; i < numMolecules; i++) {
system.addParticle(1.0);
system.addParticle(1.0);
nonbonded->addParticle(-1.0, 0.2, 0.2);
nonbonded->addParticle(1.0, 0.2, 0.2);
positions[2*i] = Vec3(boxSize*genrand_real2(sfmt), boxSize*genrand_real2(sfmt), boxSize*genrand_real2(sfmt));
positions[2*i+1] = Vec3(positions[2*i][0]+1.0, positions[2*i][1], positions[2*i][2]);
system.addConstraint(2*i, 2*i+1, 1.0);
}
// Minimize it and verify that the energy has decreased.
VerletIntegrator integrator(0.01);
Context context(system, integrator, platform);
context.setPositions(positions);
State initialState = context.getState(State::Forces | State::Energy);
LocalEnergyMinimizer::minimize(context, tolerance);
State finalState = context.getState(State::Forces | State::Energy | State::Positions);
ASSERT(finalState.getPotentialEnergy() < initialState.getPotentialEnergy());
// Compute the force magnitude, subtracting off any component parallel to a constraint, and
// check that it satisfies the requested tolerance.
double forceNorm = 0.0;
for (int i = 0; i < numParticles; i += 2) {
Vec3 dir = finalState.getPositions()[i+1]-finalState.getPositions()[i];
double distance = sqrt(dir.dot(dir));
dir *= 1.0/distance;
Vec3 f = finalState.getForces()[i];
f -= dir*dir.dot(f);
forceNorm += f.dot(f);
f = finalState.getForces()[i+1];
f -= dir*dir.dot(f);
forceNorm += f.dot(f);
}
forceNorm = sqrt(forceNorm/(5*numMolecules));
ASSERT(forceNorm < 2*tolerance);
}
void testVirtualSites() {
const int numMolecules = 25;
const int numParticles = numMolecules*3;
const double cutoff = 2.0;
const double boxSize = 4.0;
const double tolerance = 10;
System system;
system.setDefaultPeriodicBoxVectors(Vec3(boxSize, 0, 0), Vec3(0, boxSize, 0), Vec3(0, 0, boxSize));
NonbondedForce* nonbonded = new NonbondedForce();
nonbonded->setCutoffDistance(cutoff);
nonbonded->setNonbondedMethod(NonbondedForce::CutoffPeriodic);
system.addForce(nonbonded);
// Create a cloud of molecules.
OpenMM_SFMT::SFMT sfmt;
init_gen_rand(0, sfmt);
vector<Vec3> positions(numParticles);
for (int i = 0; i < numMolecules; i++) {
system.addParticle(1.0);
system.addParticle(1.0);
system.addParticle(0.0);
nonbonded->addParticle(-1.0, 0.2, 0.2);
nonbonded->addParticle(0.5, 0.2, 0.2);
nonbonded->addParticle(0.5, 0.2, 0.2);
positions[3*i] = Vec3(boxSize*genrand_real2(sfmt), boxSize*genrand_real2(sfmt), boxSize*genrand_real2(sfmt));
positions[3*i+1] = Vec3(positions[3*i][0]+1.0, positions[3*i][1], positions[3*i][2]);
positions[3*i+2] = Vec3();
system.addConstraint(3*i, 3*i+1, 1.0);
system.setVirtualSite(3*i+2, new TwoParticleAverageSite(3*i, 3*i+1, 0.5, 0.5));
}
// Minimize it and verify that the energy has decreased.
VerletIntegrator integrator(0.01);
Context context(system, integrator, platform);
context.setPositions(positions);
context.applyConstraints(1e-5);
State initialState = context.getState(State::Forces | State::Energy);
LocalEnergyMinimizer::minimize(context, tolerance);
State finalState = context.getState(State::Forces | State::Energy | State::Positions);
ASSERT(finalState.getPotentialEnergy() < initialState.getPotentialEnergy());
// Compute the force magnitude, subtracting off any component parallel to a constraint, and
// check that it satisfies the requested tolerance.
double forceNorm = 0.0;
for (int i = 0; i < numParticles; i += 3) {
Vec3 dir = finalState.getPositions()[i+1]-finalState.getPositions()[i];
double distance = sqrt(dir.dot(dir));
dir *= 1.0/distance;
Vec3 f = finalState.getForces()[i];
f -= dir*dir.dot(f);
forceNorm += f.dot(f);
f = finalState.getForces()[i+1];
f -= dir*dir.dot(f);
forceNorm += f.dot(f);
// Check the virtual site location.
ASSERT_EQUAL_VEC((finalState.getPositions()[i+1]+finalState.getPositions()[i])*0.5, finalState.getPositions()[i+2], 1e-5);
}
forceNorm = sqrt(forceNorm/(5*numMolecules));
ASSERT(forceNorm < 2*tolerance);
}
void runPlatformTests();
int main(int argc, char* argv[]) {
try {
initializeTests(argc, argv);
testHarmonicBonds();
testLargeSystem();
testVirtualSites();
runPlatformTests();
}
catch(const exception& e) {
cout << "exception: " << e.what() << endl;
return 1;
}
cout << "Done" << endl;
return 0;
}
tests/TestMonteCarloAnisotropicBarostat.h 0 → 100644
View file @ 5e1a87fb
/* -------------------------------------------------------------------------- *
* OpenMM *
* -------------------------------------------------------------------------- *
* This is part of the OpenMM molecular simulation toolkit originating from *
* Simbios, the NIH National Center for Physics-Based Simulation of *
* Biological Structures at Stanford, funded under the NIH Roadmap for *
* Medical Research, grant U54 GM072970. See https://simtk.org. *
* *
* Portions copyright (c) 2008-2015 Stanford University and the Authors. *
* Authors: Peter Eastman, Lee-Ping Wang *
* Contributors: *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* copy of this software and associated documentation files (the "Software"), *
* to deal in the Software without restriction, including without limitation *
* the rights to use, copy, modify, merge, publish, distribute, sublicense, *
* and/or sell copies of the Software, and to permit persons to whom the *
* Software is furnished to do so, subject to the following conditions: *
* *
* The above copyright notice and this permission notice shall be included in *
* all copies or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
* THE AUTHORS, CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE *
* USE OR OTHER DEALINGS IN THE SOFTWARE. *
* -------------------------------------------------------------------------- */
#include "openmm/internal/AssertionUtilities.h"
#include "openmm/CustomExternalForce.h"
#include "openmm/MonteCarloBarostat.h"
#include "openmm/MonteCarloAnisotropicBarostat.h"
#include "openmm/Context.h"
#include "openmm/NonbondedForce.h"
#include "openmm/System.h"
#include "openmm/LangevinIntegrator.h"
#include "openmm/VerletIntegrator.h"
#include "sfmt/SFMT.h"
#include "SimTKOpenMMRealType.h"
#include <iostream>
#include <vector>
using namespace OpenMM;
using namespace std;
void testIdealGas() {
const int numParticles = 64;
const int frequency = 10;
const int steps = 1000;
const double pressure = 1.5;
const double pressureInMD = pressure*(AVOGADRO*1e-25); // pressure in kJ/mol/nm^3
const double temp[] = {300.0, 600.0, 1000.0};
const double initialVolume = numParticles*BOLTZ*temp[1]/pressureInMD;
const double initialLength = std::pow(initialVolume, 1.0/3.0);
// Create a gas of noninteracting particles.
System system;
system.setDefaultPeriodicBoxVectors(Vec3(initialLength, 0, 0), Vec3(0, 0.5*initialLength, 0), Vec3(0, 0, 2*initialLength));
vector<Vec3> positions(numParticles);
OpenMM_SFMT::SFMT sfmt;
init_gen_rand(0, sfmt);
for (int i = 0; i < numParticles; ++i) {
system.addParticle(1.0);
positions[i] = Vec3(initialLength*genrand_real2(sfmt), 0.5*initialLength*genrand_real2(sfmt), 2*initialLength*genrand_real2(sfmt));
}
MonteCarloAnisotropicBarostat* barostat = new MonteCarloAnisotropicBarostat(Vec3(pressure, pressure, pressure), temp[0], true, true, true, frequency);
system.addForce(barostat);
ASSERT(barostat->usesPeriodicBoundaryConditions());
ASSERT(system.usesPeriodicBoundaryConditions());
// Test it for three different temperatures.
for (int i = 0; i < 3; i++) {
barostat->setTemperature(temp[i]);
LangevinIntegrator integrator(temp[i], 0.1, 0.01);
Context context(system, integrator, platform);
context.setPositions(positions);
// Let it equilibrate.
integrator.step(10000);
// Now run it for a while and see if the volume is correct.
double volume = 0.0;
for (int j = 0; j < steps; ++j) {
Vec3 box[3];
context.getState(0).getPeriodicBoxVectors(box[0], box[1], box[2]);
volume += box[0][0]*box[1][1]*box[2][2];
integrator.step(frequency);
}
volume /= steps;
double expected = (numParticles+1)*BOLTZ*temp[i]/pressureInMD;
ASSERT_USUALLY_EQUAL_TOL(expected, volume, 3/std::sqrt((double) steps));
}
}
void testIdealGasAxis(int axis) {
// Test scaling just one axis.
const int numParticles = 64;
const int frequency = 10;
const int steps = 1000;
const double pressure = 1.5;
const double pressureInMD = pressure*(AVOGADRO*1e-25); // pressure in kJ/mol/nm^3
const double temp[] = {300.0, 600.0, 1000.0};
const double initialVolume = numParticles*BOLTZ*temp[1]/pressureInMD;
const double initialLength = std::pow(initialVolume, 1.0/3.0);
const bool scaleX = (axis == 0);
const bool scaleY = (axis == 1);
const bool scaleZ = (axis == 2);
double boxX;
double boxY;
double boxZ;
// Create a gas of noninteracting particles.
System system;
system.setDefaultPeriodicBoxVectors(Vec3(initialLength, 0, 0), Vec3(0, 0.5*initialLength, 0), Vec3(0, 0, 2*initialLength));
vector<Vec3> positions(numParticles);
OpenMM_SFMT::SFMT sfmt;
init_gen_rand(0, sfmt);
for (int i = 0; i < numParticles; ++i) {
system.addParticle(1.0);
positions[i] = Vec3(initialLength*genrand_real2(sfmt), 0.5*initialLength*genrand_real2(sfmt), 2*initialLength*genrand_real2(sfmt));
}
MonteCarloAnisotropicBarostat* barostat = new MonteCarloAnisotropicBarostat(Vec3(pressure, pressure, pressure), temp[0], scaleX, scaleY, scaleZ, frequency);
system.addForce(barostat);
ASSERT(barostat->usesPeriodicBoundaryConditions());
ASSERT(system.usesPeriodicBoundaryConditions());
// Test it for three different temperatures.
for (int i = 0; i < 3; i++) {
barostat->setTemperature(temp[i]);
LangevinIntegrator integrator(temp[i], 0.1, 0.01);
Context context(system, integrator, platform);
context.setPositions(positions);
// Let it equilibrate.
integrator.step(10000);
// Now run it for a while and see if the volume is correct.
double volume = 0.0;
for (int j = 0; j < steps; ++j) {
Vec3 box[3];
context.getState(0).getPeriodicBoxVectors(box[0], box[1], box[2]);
boxX = box[0][0];
boxY = box[1][1];
boxZ = box[2][2];
volume += box[0][0]*box[1][1]*box[2][2];
integrator.step(frequency);
}
volume /= steps;
double expected = (numParticles+1)*BOLTZ*temp[i]/pressureInMD;
ASSERT_USUALLY_EQUAL_TOL(expected, volume, 3/std::sqrt((double) steps));
if (!scaleX) {
ASSERT(boxX == initialLength);
}
if (!scaleY) {
ASSERT(boxY == 0.5*initialLength);
}
if (!scaleZ) {
ASSERT(boxZ == 2*initialLength);
}
}
}
void testRandomSeed() {
const int numParticles = 8;
const double temp = 100.0;
const double pressure = 1.5;
System system;
system.setDefaultPeriodicBoxVectors(Vec3(8, 0, 0), Vec3(0, 8, 0), Vec3(0, 0, 8));
VerletIntegrator integrator(0.01);
NonbondedForce* forceField = new NonbondedForce();
forceField->setNonbondedMethod(NonbondedForce::CutoffPeriodic);
for (int i = 0; i < numParticles; ++i) {
system.addParticle(2.0);
forceField->addParticle((i%2 == 0 ? 1.0 : -1.0), 1.0, 5.0);
}
system.addForce(forceField);
MonteCarloAnisotropicBarostat* barostat = new MonteCarloAnisotropicBarostat(Vec3(pressure, pressure, pressure), temp, true, true, true, 1);
system.addForce(barostat);
ASSERT(barostat->usesPeriodicBoundaryConditions());
ASSERT(system.usesPeriodicBoundaryConditions());
vector<Vec3> positions(numParticles);
vector<Vec3> velocities(numParticles);
for (int i = 0; i < numParticles; ++i) {
positions[i] = Vec3((i%2 == 0 ? 2 : -2), (i%4 < 2 ? 2 : -2), (i < 4 ? 2 : -2));
velocities[i] = Vec3(0, 0, 0);
}
// Try twice with the same random seed.
barostat->setRandomNumberSeed(5);
Context context(system, integrator, platform);
context.setPositions(positions);
context.setVelocities(velocities);
integrator.step(10);
State state1 = context.getState(State::Positions);
context.reinitialize();
context.setPositions(positions);
context.setVelocities(velocities);
integrator.step(10);
State state2 = context.getState(State::Positions);
// Try twice with a different random seed.
barostat->setRandomNumberSeed(10);
context.reinitialize();
context.setPositions(positions);
context.setVelocities(velocities);
integrator.step(10);
State state3 = context.getState(State::Positions);
context.reinitialize();
context.setPositions(positions);
context.setVelocities(velocities);
integrator.step(10);
State state4 = context.getState(State::Positions);
// Compare the results.
for (int i = 0; i < numParticles; i++) {
for (int j = 0; j < 3; j++) {
ASSERT(state1.getPositions()[i][j] == state2.getPositions()[i][j]);
ASSERT(state3.getPositions()[i][j] == state4.getPositions()[i][j]);
ASSERT(state1.getPositions()[i][j] != state3.getPositions()[i][j]);
}
}
}
void testTriclinic() {
const int numParticles = 64;
const int frequency = 10;
const int steps = 1000;
const double pressure = 1.5;
const double pressureInMD = pressure*(AVOGADRO*1e-25); // pressure in kJ/mol/nm^3
const double temperature = 300.0;
const double initialVolume = numParticles*BOLTZ*temperature/pressureInMD;
const double initialLength = std::pow(initialVolume, 1.0/3.0);
// Create a gas of noninteracting particles.
System system;
Vec3 initialBox[3];
initialBox[0] = Vec3(initialLength, 0, 0);
initialBox[1] = Vec3(0.2*initialLength, initialLength, 0);
initialBox[2] = Vec3(0.1*initialLength, 0.3*initialLength, initialLength);
system.setDefaultPeriodicBoxVectors(initialBox[0], initialBox[1], initialBox[2]);
vector<Vec3> positions(numParticles);
OpenMM_SFMT::SFMT sfmt;
init_gen_rand(0, sfmt);
for (int i = 0; i < numParticles; ++i) {
system.addParticle(1.0);
positions[i] = Vec3(initialLength*genrand_real2(sfmt), initialLength*genrand_real2(sfmt), initialLength*genrand_real2(sfmt));
}
MonteCarloAnisotropicBarostat* barostat = new MonteCarloAnisotropicBarostat(Vec3(pressure, pressure, pressure), temperature, true, true, true, frequency);
system.addForce(barostat);
// Run a simulation
LangevinIntegrator integrator(temperature, 0.1, 0.01);
Context context(system, integrator, platform);
context.setPositions(positions);
// Let it equilibrate.
integrator.step(10000);
// Now run it for a while and see if the volume is correct.
double volume = 0.0;
for (int j = 0; j < steps; ++j) {
Vec3 box[3];
context.getState(0).getPeriodicBoxVectors(box[0], box[1], box[2]);
volume += box[0][0]*box[1][1]*box[2][2];
integrator.step(frequency);
}
volume /= steps;
double expected = (numParticles+1)*BOLTZ*temperature/pressureInMD;
ASSERT_USUALLY_EQUAL_TOL(expected, volume, 3/std::sqrt((double) steps));
// Make sure the box vectors have been scaled consistently.
State state = context.getState(State::Positions);
Vec3 box[3];
state.getPeriodicBoxVectors(box[0], box[1], box[2]);
double xscale = box[2][0]/(0.1*initialLength);
double yscale = box[2][1]/(0.3*initialLength);
double zscale = box[2][2]/(1.0*initialLength);
for (int i = 0; i < 3; i++) {
ASSERT_EQUAL_VEC(Vec3(xscale*initialBox[i][0], yscale*initialBox[i][1], zscale*initialBox[i][2]), box[i], 1e-5);
}
// The barostat should have put all particles inside the first periodic box. One integration step
// has happened since then, so they may have moved slightly outside it.
for (int i = 0; i < numParticles; i++) {
Vec3 pos = state.getPositions()[i];
ASSERT(pos[2]/box[2][2] > -1 && pos[2]/box[2][2] < 2);
pos -= box[2]*floor(pos[2]/box[2][2]);
ASSERT(pos[1]/box[1][1] > -1 && pos[1]/box[1][1] < 2);
pos -= box[1]*floor(pos[1]/box[1][1]);
ASSERT(pos[0]/box[0][0] > -1 && pos[0]/box[0][0] < 2);
}
}
/**
* Run a constant pressure simulation on an anisotropic Einstein crystal
* using isotropic and anisotropic barostats. There are a total of 15 simulations:
*
* 1) 3 pressures: 9.0, 10.0, 11.0 bar, for each of the following groups:
* 2) 3 groups of simulations that scale just one axis: x, y, z
* 3) 1 group of simulations that scales all three axes in the anisotropic barostat
* 4) 1 group of simulations that scales all three axes in the isotropic barostat
*
* Results that we will check:
*
* a) In each group of simulations, the volume should decrease with increasing pressure
* b) In the three simulation groups that scale just one axis, the compressibility (i.e. incremental volume change
* with increasing pressure) should go like kx > ky > kz (because the spring constant is largest in the z-direction)
* c) The anisotropic barostat should produce the same result as the isotropic barostat when all three axes are scaled
*/
void testEinsteinCrystal() {
const int numParticles = 64;
const int frequency = 2;
const int equil = 10000;
const int steps = 5000;
const double pressure = 10.0;
const double pressureInMD = pressure*(AVOGADRO*1e-25); // pressure in kJ/mol/nm^3
const double temp = 300.0; // Only test one temperature since we're looking at three pressures.
const double pres3[] = {2.0, 8.0, 15.0};
const double initialVolume = numParticles*BOLTZ*temp/pressureInMD;
const double initialLength = std::pow(initialVolume, 1.0/3.0);
vector<double> initialPositions(3);
vector<double> results;
// Run four groups of anisotropic simulations; scaling just x, y, z, then all three.
for (int a = 0; a < 4; a++) {
// Test barostat for three different pressures.
for (int p = 0; p < 3; p++) {
// Create a system of noninteracting particles attached by harmonic springs to their initial positions.
System system;
system.setDefaultPeriodicBoxVectors(Vec3(initialLength, 0, 0), Vec3(0, initialLength, 0), Vec3(0, 0, initialLength));
vector<Vec3> positions(numParticles);
OpenMM_SFMT::SFMT sfmt;
init_gen_rand(0, sfmt);
// Anisotropic force constants.
CustomExternalForce* force = new CustomExternalForce("0.005*(x-x0)^2 + 0.01*(y-y0)^2 + 0.02*(z-z0)^2");
force->addPerParticleParameter("x0");
force->addPerParticleParameter("y0");
force->addPerParticleParameter("z0");
NonbondedForce* nb = new NonbondedForce();
nb->setNonbondedMethod(NonbondedForce::CutoffPeriodic);
for (int i = 0; i < numParticles; ++i) {
system.addParticle(1.0);
positions[i] = Vec3(((i/16)%4+0.5)*initialLength/4, ((i/4)%4+0.5)*initialLength/4, (i%4+0.5)*initialLength/4);
initialPositions[0] = positions[i][0];
initialPositions[1] = positions[i][1];
initialPositions[2] = positions[i][2];
force->addParticle(i, initialPositions);
nb->addParticle(0, initialLength/6, 0.1);
}
system.addForce(force);
system.addForce(nb);
// Create the barostat.
MonteCarloAnisotropicBarostat* barostat = new MonteCarloAnisotropicBarostat(Vec3(pres3[p], pres3[p], pres3[p]), temp, (a==0||a==3), (a==1||a==3), (a==2||a==3), frequency);
system.addForce(barostat);
barostat->setTemperature(temp);
LangevinIntegrator integrator(temp, 0.1, 0.01);
Context context(system, integrator, platform);
context.setPositions(positions);
// Let it equilibrate.
integrator.step(equil);
// Now run it for a while and see if the volume is correct.
double volume = 0.0;
for (int j = 0; j < steps; ++j) {
Vec3 box[3];
context.getState(0).getPeriodicBoxVectors(box[0], box[1], box[2]);
volume += box[0][0]*box[1][1]*box[2][2];
integrator.step(frequency);
}
volume /= steps;
results.push_back(volume);
}
}
for (int p = 0; p < 3; p++) {
// Create a system of noninteracting particles attached by harmonic springs to their initial positions.
System system;
system.setDefaultPeriodicBoxVectors(Vec3(initialLength, 0, 0), Vec3(0, initialLength, 0), Vec3(0, 0, initialLength));
vector<Vec3> positions(numParticles);
OpenMM_SFMT::SFMT sfmt;
init_gen_rand(0, sfmt);
// Anisotropic force constants.
CustomExternalForce* force = new CustomExternalForce("0.005*(x-x0)^2 + 0.01*(y-y0)^2 + 0.02*(z-z0)^2");
force->addPerParticleParameter("x0");
force->addPerParticleParameter("y0");
force->addPerParticleParameter("z0");
NonbondedForce* nb = new NonbondedForce();
nb->setNonbondedMethod(NonbondedForce::CutoffPeriodic);
for (int i = 0; i < numParticles; ++i) {
system.addParticle(1.0);
positions[i] = Vec3(((i/16)%4+0.5)*initialLength/4, ((i/4)%4+0.5)*initialLength/4, (i%4+0.5)*initialLength/4);
initialPositions[0] = positions[i][0];
initialPositions[1] = positions[i][1];
initialPositions[2] = positions[i][2];
force->addParticle(i, initialPositions);
nb->addParticle(0, initialLength/6, 0.1);
}
system.addForce(force);
system.addForce(nb);
// Create the barostat.
MonteCarloBarostat* barostat = new MonteCarloBarostat(pres3[p], temp, frequency);
system.addForce(barostat);
barostat->setTemperature(temp);
LangevinIntegrator integrator(temp, 0.1, 0.001);
Context context(system, integrator, platform);
context.setPositions(positions);
// Let it equilibrate.
integrator.step(equil);
// Now run it for a while and see if the volume is correct.
double volume = 0.0;
for (int j = 0; j < steps; ++j) {
Vec3 box[3];
context.getState(0).getPeriodicBoxVectors(box[0], box[1], box[2]);
volume += box[0][0]*box[1][1]*box[2][2];
integrator.step(frequency);
}
volume /= steps;
results.push_back(volume);
}
// Check to see if volumes decrease with increasing pressure.
ASSERT_USUALLY_TRUE(results[0] > results[1]);
ASSERT_USUALLY_TRUE(results[1] > results[2]);
ASSERT_USUALLY_TRUE(results[3] > results[4]);
ASSERT_USUALLY_TRUE(results[4] > results[5]);
ASSERT_USUALLY_TRUE(results[6] > results[7]);
ASSERT_USUALLY_TRUE(results[7] > results[8]);
// Check to see if incremental volume changes with increasing pressure go like kx > ky > kz.
ASSERT_USUALLY_TRUE((results[0] - results[1]) > (results[3] - results[4]));
ASSERT_USUALLY_TRUE((results[1] - results[2]) > (results[4] - results[5]));
ASSERT_USUALLY_TRUE((results[3] - results[4]) > (results[6] - results[7]));
ASSERT_USUALLY_TRUE((results[4] - results[5]) > (results[7] - results[8]));
// Check to see if the volumes are equal for isotropic and anisotropic (all axis).
ASSERT_USUALLY_EQUAL_TOL(results[9], results[12], 3/std::sqrt((double) steps));
ASSERT_USUALLY_EQUAL_TOL(results[10], results[13], 3/std::sqrt((double) steps));
ASSERT_USUALLY_EQUAL_TOL(results[11], results[14], 3/std::sqrt((double) steps));
}
void runPlatformTests();
int main(int argc, char* argv[]) {
try {
initializeTests(argc, argv);
testIdealGas();
testIdealGasAxis(0);
testIdealGasAxis(1);
testIdealGasAxis(2);
testRandomSeed();
testTriclinic();
//testEinsteinCrystal();
runPlatformTests();
}
catch(const exception& e) {
cout << "exception: " << e.what() << endl;
return 1;
}
cout << "Done" << endl;
return 0;
}
tests/TestMonteCarloBarostat.h 0 → 100644
View file @ 5e1a87fb
/* -------------------------------------------------------------------------- *
* OpenMM *
* -------------------------------------------------------------------------- *
* This is part of the OpenMM molecular simulation toolkit originating from *
* Simbios, the NIH National Center for Physics-Based Simulation of *
* Biological Structures at Stanford, funded under the NIH Roadmap for *
* Medical Research, grant U54 GM072970. See https://simtk.org. *
* *
* Portions copyright (c) 2008-2015 Stanford University and the Authors. *
* Authors: Peter Eastman *
* Contributors: *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* copy of this software and associated documentation files (the "Software"), *
* to deal in the Software without restriction, including without limitation *
* the rights to use, copy, modify, merge, publish, distribute, sublicense, *
* and/or sell copies of the Software, and to permit persons to whom the *
* Software is furnished to do so, subject to the following conditions: *
* *
* The above copyright notice and this permission notice shall be included in *
* all copies or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
* THE AUTHORS, CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE *
* USE OR OTHER DEALINGS IN THE SOFTWARE. *
* -------------------------------------------------------------------------- */
#include "openmm/internal/AssertionUtilities.h"
#include "openmm/MonteCarloBarostat.h"
#include "openmm/Context.h"
#include "openmm/NonbondedForce.h"
#include "openmm/System.h"
#include "openmm/LangevinIntegrator.h"
#include "openmm/VerletIntegrator.h"
#include "sfmt/SFMT.h"
#include "SimTKOpenMMRealType.h"
#include <iostream>
#include <vector>
using namespace OpenMM;
using namespace std;
void testChangingBoxSize() {
System system;
system.setDefaultPeriodicBoxVectors(Vec3(4, 0, 0), Vec3(0, 5, 0), Vec3(0, 0, 6));
system.addParticle(1.0);
NonbondedForce* nb = new NonbondedForce();
nb->setNonbondedMethod(NonbondedForce::CutoffPeriodic);
nb->setCutoffDistance(2.0);
nb->addParticle(1, 0.5, 0.5);
system.addForce(nb);
LangevinIntegrator integrator(300.0, 1.0, 0.01);
Context context(system, integrator, platform);
vector<Vec3> positions;
positions.push_back(Vec3());
context.setPositions(positions);
Vec3 x, y, z;
context.getState(State::Forces).getPeriodicBoxVectors(x, y, z);
ASSERT_EQUAL_VEC(Vec3(4, 0, 0), x, 0);
ASSERT_EQUAL_VEC(Vec3(0, 5, 0), y, 0);
ASSERT_EQUAL_VEC(Vec3(0, 0, 6), z, 0);
context.setPeriodicBoxVectors(Vec3(7, 0, 0), Vec3(0, 8, 0), Vec3(0, 0, 9));
context.getState(State::Forces).getPeriodicBoxVectors(x, y, z);
ASSERT_EQUAL_VEC(Vec3(7, 0, 0), x, 0);
ASSERT_EQUAL_VEC(Vec3(0, 8, 0), y, 0);
ASSERT_EQUAL_VEC(Vec3(0, 0, 9), z, 0);
// Shrinking the box too small should produce an exception.
context.setPeriodicBoxVectors(Vec3(7, 0, 0), Vec3(0, 3.9, 0), Vec3(0, 0, 9));
bool ok = true;
try {
context.getState(State::Forces).getPeriodicBoxVectors(x, y, z);
ok = false;
}
catch (exception& ex) {
}
ASSERT(ok);
}
void testIdealGas() {
const int numParticles = 64;
const int frequency = 10;
const int steps = 1000;
const double pressure = 1.5;
const double pressureInMD = pressure*(AVOGADRO*1e-25); // pressure in kJ/mol/nm^3
const double temp[] = {300.0, 600.0, 1000.0};
const double initialVolume = numParticles*BOLTZ*temp[1]/pressureInMD;
const double initialLength = std::pow(initialVolume, 1.0/3.0);
// Create a gas of noninteracting particles.
System system;
system.setDefaultPeriodicBoxVectors(Vec3(initialLength, 0, 0), Vec3(0, 0.5*initialLength, 0), Vec3(0, 0, 2*initialLength));
vector<Vec3> positions(numParticles);
OpenMM_SFMT::SFMT sfmt;
init_gen_rand(0, sfmt);
for (int i = 0; i < numParticles; ++i) {
system.addParticle(1.0);
positions[i] = Vec3(initialLength*genrand_real2(sfmt), 0.5*initialLength*genrand_real2(sfmt), 2*initialLength*genrand_real2(sfmt));
}
MonteCarloBarostat* barostat = new MonteCarloBarostat(pressure, temp[0], frequency);
system.addForce(barostat);
ASSERT(barostat->usesPeriodicBoundaryConditions());
ASSERT(system.usesPeriodicBoundaryConditions());
// Test it for three different temperatures.
for (int i = 0; i < 3; i++) {
barostat->setTemperature(temp[i]);
LangevinIntegrator integrator(temp[i], 0.1, 0.01);
Context context(system, integrator, platform);
context.setPositions(positions);
// Let it equilibrate.
integrator.step(10000);
// Now run it for a while and see if the volume is correct.
double volume = 0.0;
for (int j = 0; j < steps; ++j) {
Vec3 box[3];
context.getState(0).getPeriodicBoxVectors(box[0], box[1], box[2]);
volume += box[0][0]*box[1][1]*box[2][2];
ASSERT_EQUAL_TOL(0.5*box[0][0], box[1][1], 1e-5);
ASSERT_EQUAL_TOL(2*box[0][0], box[2][2], 1e-5);
integrator.step(frequency);
}
volume /= steps;
double expected = (numParticles+1)*BOLTZ*temp[i]/pressureInMD;
ASSERT_USUALLY_EQUAL_TOL(expected, volume, 3/std::sqrt((double) steps));
}
}
void testRandomSeed() {
const int numParticles = 8;
const double temp = 100.0;
const double pressure = 1.5;
System system;
system.setDefaultPeriodicBoxVectors(Vec3(8, 0, 0), Vec3(0, 8, 0), Vec3(0, 0, 8));
VerletIntegrator integrator(0.01);
NonbondedForce* forceField = new NonbondedForce();
forceField->setNonbondedMethod(NonbondedForce::CutoffPeriodic);
for (int i = 0; i < numParticles; ++i) {
system.addParticle(2.0);
forceField->addParticle((i%2 == 0 ? 1.0 : -1.0), 1.0, 5.0);
}
system.addForce(forceField);
MonteCarloBarostat* barostat = new MonteCarloBarostat(pressure, temp, 1);
system.addForce(barostat);
ASSERT(barostat->usesPeriodicBoundaryConditions());
ASSERT(system.usesPeriodicBoundaryConditions());
vector<Vec3> positions(numParticles);
vector<Vec3> velocities(numParticles);
for (int i = 0; i < numParticles; ++i) {
positions[i] = Vec3((i%2 == 0 ? 2 : -2), (i%4 < 2 ? 2 : -2), (i < 4 ? 2 : -2));
velocities[i] = Vec3(0, 0, 0);
}
// Try twice with the same random seed.
barostat->setRandomNumberSeed(5);
Context context(system, integrator, platform);
context.setPositions(positions);
context.setVelocities(velocities);
integrator.step(10);
State state1 = context.getState(State::Positions);
context.reinitialize();
context.setPositions(positions);
context.setVelocities(velocities);
integrator.step(10);
State state2 = context.getState(State::Positions);
// Try twice with a different random seed.
barostat->setRandomNumberSeed(10);
context.reinitialize();
context.setPositions(positions);
context.setVelocities(velocities);
integrator.step(10);
State state3 = context.getState(State::Positions);
context.reinitialize();
context.setPositions(positions);
context.setVelocities(velocities);
integrator.step(10);
State state4 = context.getState(State::Positions);
// Compare the results.
for (int i = 0; i < numParticles; i++) {
for (int j = 0; j < 3; j++) {
ASSERT(state1.getPositions()[i][j] == state2.getPositions()[i][j]);
ASSERT(state3.getPositions()[i][j] == state4.getPositions()[i][j]);
ASSERT(state1.getPositions()[i][j] != state3.getPositions()[i][j]);
}
}
}
void testWater() {
const int gridSize = 8;
const int numMolecules = gridSize*gridSize*gridSize;
const int frequency = 10;
const int steps = 400;
const double temp = 273.15;
const double pressure = 3;
const double spacing = 0.32;
const double angle = 109.47*M_PI/180;
const double dOH = 0.1;
const double dHH = dOH*2*std::sin(0.5*angle);
// Create a box of SPC water molecules.
System system;
system.setDefaultPeriodicBoxVectors(Vec3(gridSize*spacing, 0, 0), Vec3(0, gridSize*spacing, 0), Vec3(0, 0, gridSize*spacing));
NonbondedForce* nonbonded = new NonbondedForce();
nonbonded->setNonbondedMethod(NonbondedForce::CutoffPeriodic);
nonbonded->setUseDispersionCorrection(true);
vector<Vec3> positions;
Vec3 offset1(dOH, 0, 0);
Vec3 offset2(dOH*std::cos(angle), dOH*std::sin(angle), 0);
for (int i = 0; i < gridSize; ++i) {
for (int j = 0; j < gridSize; ++j) {
for (int k = 0; k < gridSize; ++k) {
int firstParticle = system.getNumParticles();
system.addParticle(16.0);
system.addParticle(1.0);
system.addParticle(1.0);
nonbonded->addParticle(-0.82, 0.316557, 0.650194);
nonbonded->addParticle(0.41, 1, 0);
nonbonded->addParticle(0.41, 1, 0);
Vec3 pos = Vec3(spacing*i, spacing*j, spacing*k);
positions.push_back(pos);
positions.push_back(pos+offset1);
positions.push_back(pos+offset2);
system.addConstraint(firstParticle, firstParticle+1, dOH);
system.addConstraint(firstParticle, firstParticle+2, dOH);
system.addConstraint(firstParticle+1, firstParticle+2, dHH);
nonbonded->addException(firstParticle, firstParticle+1, 0, 1, 0);
nonbonded->addException(firstParticle, firstParticle+2, 0, 1, 0);
nonbonded->addException(firstParticle+1, firstParticle+2, 0, 1, 0);
}
}
}
system.addForce(nonbonded);
MonteCarloBarostat* barostat = new MonteCarloBarostat(pressure, temp, frequency);
system.addForce(barostat);
// Simulate it and see if the density matches the expected value (1 g/mL).
LangevinIntegrator integrator(temp, 1.0, 0.002);
Context context(system, integrator, platform);
context.setPositions(positions);
integrator.step(2000);
double volume = 0.0;
for (int j = 0; j < steps; ++j) {
Vec3 box[3];
context.getState(0).getPeriodicBoxVectors(box[0], box[1], box[2]);
volume += box[0][0]*box[1][1]*box[2][2];
integrator.step(frequency);
}
volume /= steps;
double density = numMolecules*18/(AVOGADRO*volume*1e-21);
ASSERT_USUALLY_EQUAL_TOL(1.0, density, 0.02);
}
void runPlatformTests();
int main(int argc, char* argv[]) {
try {
initializeTests(argc, argv);
testChangingBoxSize();
testIdealGas();
testRandomSeed();
// Don't run testWater() here, because it's very slow on Reference platform.
// Individual platforms can run it from runPlatformTests().
runPlatformTests();
}
catch(const exception& e) {
cout << "exception: " << e.what() << endl;
return 1;
}
cout << "Done" << endl;
return 0;
}
tests/TestNonbondedForce.h 0 → 100644
View file @ 5e1a87fb
/* -------------------------------------------------------------------------- *
* OpenMM *
* -------------------------------------------------------------------------- *
* This is part of the OpenMM molecular simulation toolkit originating from *
* Simbios, the NIH National Center for Physics-Based Simulation of *
* Biological Structures at Stanford, funded under the NIH Roadmap for *
* Medical Research, grant U54 GM072970. See https://simtk.org. *
* *
* Portions copyright (c) 2008-2015 Stanford University and the Authors. *
* Authors: Peter Eastman *
* Contributors: *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* copy of this software and associated documentation files (the "Software"), *
* to deal in the Software without restriction, including without limitation *
* the rights to use, copy, modify, merge, publish, distribute, sublicense, *
* and/or sell copies of the Software, and to permit persons to whom the *
* Software is furnished to do so, subject to the following conditions: *
* *
* The above copyright notice and this permission notice shall be included in *
* all copies or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
* THE AUTHORS, CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE *
* USE OR OTHER DEALINGS IN THE SOFTWARE. *
* -------------------------------------------------------------------------- */
#include "openmm/internal/AssertionUtilities.h"
#include "openmm/Context.h"
#include "ReferencePlatform.h"
#include "openmm/HarmonicBondForce.h"
#include "openmm/NonbondedForce.h"
#include "openmm/System.h"
#include "openmm/VerletIntegrator.h"
#include "SimTKOpenMMRealType.h"
#include "sfmt/SFMT.h"
#include <iostream>
#include <vector>
using namespace OpenMM;
using namespace std;
const double TOL = 1e-5;
void testCoulomb() {
System system;
system.addParticle(1.0);
system.addParticle(1.0);
VerletIntegrator integrator(0.01);
NonbondedForce* forceField = new NonbondedForce();
forceField->addParticle(0.5, 1, 0);
forceField->addParticle(-1.5, 1, 0);
system.addForce(forceField);
ASSERT(!forceField->usesPeriodicBoundaryConditions());
ASSERT(!system.usesPeriodicBoundaryConditions());
Context context(system, integrator, platform);
vector<Vec3> positions(2);
positions[0] = Vec3(0, 0, 0);
positions[1] = Vec3(2, 0, 0);
context.setPositions(positions);
State state = context.getState(State::Forces | State::Energy);
const vector<Vec3>& forces = state.getForces();
double force = ONE_4PI_EPS0*(-0.75)/4.0;
ASSERT_EQUAL_VEC(Vec3(-force, 0, 0), forces[0], TOL);
ASSERT_EQUAL_VEC(Vec3(force, 0, 0), forces[1], TOL);
ASSERT_EQUAL_TOL(ONE_4PI_EPS0*(-0.75)/2.0, state.getPotentialEnergy(), TOL);
}
void testLJ() {
System system;
system.addParticle(1.0);
system.addParticle(1.0);
VerletIntegrator integrator(0.01);
NonbondedForce* forceField = new NonbondedForce();
forceField->addParticle(0, 1.2, 1);
forceField->addParticle(0, 1.4, 2);
system.addForce(forceField);
ASSERT(!forceField->usesPeriodicBoundaryConditions());
ASSERT(!system.usesPeriodicBoundaryConditions());
Context context(system, integrator, platform);
vector<Vec3> positions(2);
positions[0] = Vec3(0, 0, 0);
positions[1] = Vec3(2, 0, 0);
context.setPositions(positions);
State state = context.getState(State::Forces | State::Energy);
const vector<Vec3>& forces = state.getForces();
double x = 1.3/2.0;
double eps = SQRT_TWO;
double force = 4.0*eps*(12*std::pow(x, 12.0)-6*std::pow(x, 6.0))/2.0;
ASSERT_EQUAL_VEC(Vec3(-force, 0, 0), forces[0], TOL);
ASSERT_EQUAL_VEC(Vec3(force, 0, 0), forces[1], TOL);
ASSERT_EQUAL_TOL(4.0*eps*(std::pow(x, 12.0)-std::pow(x, 6.0)), state.getPotentialEnergy(), TOL);
}
void testExclusionsAnd14() {
System system;
NonbondedForce* nonbonded = new NonbondedForce();
for (int i = 0; i < 5; ++i) {
system.addParticle(1.0);
nonbonded->addParticle(0, 1.5, 0);
}
vector<pair<int, int> > bonds;
bonds.push_back(pair<int, int>(0, 1));
bonds.push_back(pair<int, int>(1, 2));
bonds.push_back(pair<int, int>(2, 3));
bonds.push_back(pair<int, int>(3, 4));
nonbonded->createExceptionsFromBonds(bonds, 0.0, 0.0);
int first14, second14;
for (int i = 0; i < nonbonded->getNumExceptions(); i++) {
int particle1, particle2;
double chargeProd, sigma, epsilon;
nonbonded->getExceptionParameters(i, particle1, particle2, chargeProd, sigma, epsilon);
if ((particle1 == 0 && particle2 == 3) || (particle1 == 3 && particle2 == 0))
first14 = i;
if ((particle1 == 1 && particle2 == 4) || (particle1 == 4 && particle2 == 1))
second14 = i;
}
system.addForce(nonbonded);
VerletIntegrator integrator(0.01);
Context context(system, integrator, platform);
for (int i = 1; i < 5; ++i) {
// Test LJ forces
vector<Vec3> positions(5);
const double r = 1.0;
for (int j = 0; j < 5; ++j) {
nonbonded->setParticleParameters(j, 0, 1.5, 0);
positions[j] = Vec3(0, j, 0);
}
nonbonded->setParticleParameters(0, 0, 1.5, 1);
nonbonded->setParticleParameters(i, 0, 1.5, 1);
nonbonded->setExceptionParameters(first14, 0, 3, 0, 1.5, i == 3 ? 0.5 : 0.0);
nonbonded->setExceptionParameters(second14, 1, 4, 0, 1.5, 0.0);
positions[i] = Vec3(r, 0, 0);
context.reinitialize();
context.setPositions(positions);
State state = context.getState(State::Forces | State::Energy);
const vector<Vec3>& forces = state.getForces();
double x = 1.5/r;
double eps = 1.0;
double force = 4.0*eps*(12*std::pow(x, 12.0)-6*std::pow(x, 6.0))/r;
double energy = 4.0*eps*(std::pow(x, 12.0)-std::pow(x, 6.0));
if (i == 3) {
force *= 0.5;
energy *= 0.5;
}
if (i < 3) {
force = 0;
energy = 0;
}
ASSERT_EQUAL_VEC(Vec3(-force, 0, 0), forces[0], TOL);
ASSERT_EQUAL_VEC(Vec3(force, 0, 0), forces[i], TOL);
ASSERT_EQUAL_TOL(energy, state.getPotentialEnergy(), TOL);
// Test Coulomb forces
nonbonded->setParticleParameters(0, 2, 1.5, 0);
nonbonded->setParticleParameters(i, 2, 1.5, 0);
nonbonded->setExceptionParameters(first14, 0, 3, i == 3 ? 4/1.2 : 0, 1.5, 0);
nonbonded->setExceptionParameters(second14, 1, 4, 0, 1.5, 0);
context.reinitialize();
context.setPositions(positions);
state = context.getState(State::Forces | State::Energy);
const vector<Vec3>& forces2 = state.getForces();
force = ONE_4PI_EPS0*4/(r*r);
energy = ONE_4PI_EPS0*4/r;
if (i == 3) {
force /= 1.2;
energy /= 1.2;
}
if (i < 3) {
force = 0;
energy = 0;
}
ASSERT_EQUAL_VEC(Vec3(-force, 0, 0), forces2[0], TOL);
ASSERT_EQUAL_VEC(Vec3(force, 0, 0), forces2[i], TOL);
ASSERT_EQUAL_TOL(energy, state.getPotentialEnergy(), TOL);
}
}
void testCutoff() {
System system;
system.addParticle(1.0);
system.addParticle(1.0);
system.addParticle(1.0);
VerletIntegrator integrator(0.01);
NonbondedForce* forceField = new NonbondedForce();
forceField->addParticle(1.0, 1, 0);
forceField->addParticle(1.0, 1, 0);
forceField->addParticle(1.0, 1, 0);
forceField->setNonbondedMethod(NonbondedForce::CutoffNonPeriodic);
const double cutoff = 2.9;
forceField->setCutoffDistance(cutoff);
const double eps = 50.0;
forceField->setReactionFieldDielectric(eps);
system.addForce(forceField);
ASSERT(!forceField->usesPeriodicBoundaryConditions());
ASSERT(!system.usesPeriodicBoundaryConditions());
Context context(system, integrator, platform);
vector<Vec3> positions(3);
positions[0] = Vec3(0, 0, 0);
positions[1] = Vec3(0, 2, 0);
positions[2] = Vec3(0, 3, 0);
context.setPositions(positions);
State state = context.getState(State::Forces | State::Energy);
const vector<Vec3>& forces = state.getForces();
const double krf = (1.0/(cutoff*cutoff*cutoff))*(eps-1.0)/(2.0*eps+1.0);
const double crf = (1.0/cutoff)*(3.0*eps)/(2.0*eps+1.0);
const double force1 = ONE_4PI_EPS0*(1.0)*(0.25-2.0*krf*2.0);
const double force2 = ONE_4PI_EPS0*(1.0)*(1.0-2.0*krf*1.0);
ASSERT_EQUAL_VEC(Vec3(0, -force1, 0), forces[0], TOL);
ASSERT_EQUAL_VEC(Vec3(0, force1-force2, 0), forces[1], TOL);
ASSERT_EQUAL_VEC(Vec3(0, force2, 0), forces[2], TOL);
const double energy1 = ONE_4PI_EPS0*(1.0)*(0.5+krf*4.0-crf);
const double energy2 = ONE_4PI_EPS0*(1.0)*(1.0+krf*1.0-crf);
ASSERT_EQUAL_TOL(energy1+energy2, state.getPotentialEnergy(), TOL);
}
void testCutoff14() {
System system;
VerletIntegrator integrator(0.01);
NonbondedForce* nonbonded = new NonbondedForce();
nonbonded->setNonbondedMethod(NonbondedForce::CutoffNonPeriodic);
for (int i = 0; i < 5; i++) {
system.addParticle(1.0);
nonbonded->addParticle(0, 1.5, 0);
}
const double cutoff = 3.5;
nonbonded->setCutoffDistance(cutoff);
const double eps = 30.0;
nonbonded->setReactionFieldDielectric(eps);
vector<pair<int, int> > bonds;
bonds.push_back(pair<int, int>(0, 1));
bonds.push_back(pair<int, int>(1, 2));
bonds.push_back(pair<int, int>(2, 3));
bonds.push_back(pair<int, int>(3, 4));
nonbonded->createExceptionsFromBonds(bonds, 0.0, 0.0);
int first14, second14;
for (int i = 0; i < nonbonded->getNumExceptions(); i++) {
int particle1, particle2;
double chargeProd, sigma, epsilon;
nonbonded->getExceptionParameters(i, particle1, particle2, chargeProd, sigma, epsilon);
if ((particle1 == 0 && particle2 == 3) || (particle1 == 3 && particle2 == 0))
first14 = i;
if ((particle1 == 1 && particle2 == 4) || (particle1 == 4 && particle2 == 1))
second14 = i;
}
system.addForce(nonbonded);
ASSERT(!nonbonded->usesPeriodicBoundaryConditions());
ASSERT(!system.usesPeriodicBoundaryConditions());
Context context(system, integrator, platform);
vector<Vec3> positions(5);
positions[0] = Vec3(0, 0, 0);
positions[1] = Vec3(1, 0, 0);
positions[2] = Vec3(2, 0, 0);
positions[3] = Vec3(3, 0, 0);
positions[4] = Vec3(4, 0, 0);
for (int i = 1; i < 5; ++i) {
// Test LJ forces
nonbonded->setParticleParameters(0, 0, 1.5, 1);
for (int j = 1; j < 5; ++j)
nonbonded->setParticleParameters(j, 0, 1.5, 0);
nonbonded->setParticleParameters(i, 0, 1.5, 1);
nonbonded->setExceptionParameters(first14, 0, 3, 0, 1.5, i == 3 ? 0.5 : 0.0);
nonbonded->setExceptionParameters(second14, 1, 4, 0, 1.5, 0.0);
context.reinitialize();
context.setPositions(positions);
State state = context.getState(State::Forces | State::Energy);
const vector<Vec3>& forces = state.getForces();
double r = positions[i][0];
double x = 1.5/r;
double e = 1.0;
double force = 4.0*e*(12*std::pow(x, 12.0)-6*std::pow(x, 6.0))/r;
double energy = 4.0*e*(std::pow(x, 12.0)-std::pow(x, 6.0));
if (i == 3) {
force *= 0.5;
energy *= 0.5;
}
if (i < 3 || r > cutoff) {
force = 0;
energy = 0;
}
ASSERT_EQUAL_VEC(Vec3(-force, 0, 0), forces[0], TOL);
ASSERT_EQUAL_VEC(Vec3(force, 0, 0), forces[i], TOL);
ASSERT_EQUAL_TOL(energy, state.getPotentialEnergy(), TOL);
// Test Coulomb forces
const double q = 0.7;
nonbonded->setParticleParameters(0, q, 1.5, 0);
nonbonded->setParticleParameters(i, q, 1.5, 0);
nonbonded->setExceptionParameters(first14, 0, 3, i == 3 ? q*q/1.2 : 0, 1.5, 0);
nonbonded->setExceptionParameters(second14, 1, 4, 0, 1.5, 0);
context.reinitialize();
context.setPositions(positions);
state = context.getState(State::Forces | State::Energy);
const vector<Vec3>& forces2 = state.getForces();
force = ONE_4PI_EPS0*q*q/(r*r);
energy = ONE_4PI_EPS0*q*q/r;
if (i == 3) {
force /= 1.2;
energy /= 1.2;
}
if (i < 3 || r > cutoff) {
force = 0;
energy = 0;
}
ASSERT_EQUAL_VEC(Vec3(-force, 0, 0), forces2[0], TOL);
ASSERT_EQUAL_VEC(Vec3(force, 0, 0), forces2[i], TOL);
ASSERT_EQUAL_TOL(energy, state.getPotentialEnergy(), TOL);
}
}
void testPeriodic() {
System system;
system.addParticle(1.0);
system.addParticle(1.0);
system.addParticle(1.0);
VerletIntegrator integrator(0.01);
NonbondedForce* nonbonded = new NonbondedForce();
nonbonded->addParticle(1.0, 1, 0);
nonbonded->addParticle(1.0, 1, 0);
nonbonded->addParticle(1.0, 1, 0);
nonbonded->addException(0, 1, 0.0, 1.0, 0.0);
nonbonded->setNonbondedMethod(NonbondedForce::CutoffPeriodic);
const double cutoff = 2.0;
nonbonded->setCutoffDistance(cutoff);
system.setDefaultPeriodicBoxVectors(Vec3(4, 0, 0), Vec3(0, 4, 0), Vec3(0, 0, 4));
system.addForce(nonbonded);
ASSERT(nonbonded->usesPeriodicBoundaryConditions());
ASSERT(system.usesPeriodicBoundaryConditions());
Context context(system, integrator, platform);
vector<Vec3> positions(3);
positions[0] = Vec3(0, 0, 0);
positions[1] = Vec3(2, 0, 0);
positions[2] = Vec3(3, 0, 0);
context.setPositions(positions);
State state = context.getState(State::Forces | State::Energy);
const vector<Vec3>& forces = state.getForces();
const double eps = 78.3;
const double krf = (1.0/(cutoff*cutoff*cutoff))*(eps-1.0)/(2.0*eps+1.0);
const double crf = (1.0/cutoff)*(3.0*eps)/(2.0*eps+1.0);
const double force = ONE_4PI_EPS0*(1.0)*(1.0-2.0*krf*1.0);
ASSERT_EQUAL_VEC(Vec3(force, 0, 0), forces[0], TOL);
ASSERT_EQUAL_VEC(Vec3(-force, 0, 0), forces[1], TOL);
ASSERT_EQUAL_VEC(Vec3(0, 0, 0), forces[2], TOL);
ASSERT_EQUAL_TOL(2*ONE_4PI_EPS0*(1.0)*(1.0+krf*1.0-crf), state.getPotentialEnergy(), TOL);
}
void testTriclinic() {
System system;
system.addParticle(1.0);
system.addParticle(1.0);
Vec3 a(3.1, 0, 0);
Vec3 b(0.4, 3.5, 0);
Vec3 c(-0.1, -0.5, 4.0);
system.setDefaultPeriodicBoxVectors(a, b, c);
VerletIntegrator integrator(0.01);
NonbondedForce* nonbonded = new NonbondedForce();
nonbonded->addParticle(1.0, 1, 0);
nonbonded->addParticle(1.0, 1, 0);
nonbonded->setNonbondedMethod(NonbondedForce::CutoffPeriodic);
const double cutoff = 1.5;
nonbonded->setCutoffDistance(cutoff);
system.addForce(nonbonded);
Context context(system, integrator, platform);
vector<Vec3> positions(2);
OpenMM_SFMT::SFMT sfmt;
init_gen_rand(0, sfmt);
const double eps = 78.3;
const double krf = (1.0/(cutoff*cutoff*cutoff))*(eps-1.0)/(2.0*eps+1.0);
const double crf = (1.0/cutoff)*(3.0*eps)/(2.0*eps+1.0);
for (int iteration = 0; iteration < 50; iteration++) {
// Generate random positions for the two particles.
positions[0] = a*genrand_real2(sfmt) + b*genrand_real2(sfmt) + c*genrand_real2(sfmt);
positions[1] = a*genrand_real2(sfmt) + b*genrand_real2(sfmt) + c*genrand_real2(sfmt);
context.setPositions(positions);
// Loop over all possible periodic copies and find the nearest one.
Vec3 delta;
double distance2 = 100.0;
for (int i = -1; i < 2; i++)
for (int j = -1; j < 2; j++)
for (int k = -1; k < 2; k++) {
Vec3 d = positions[1]-positions[0]+a*i+b*j+c*k;
if (d.dot(d) < distance2) {
delta = d;
distance2 = d.dot(d);
}
}
double distance = sqrt(distance2);
// See if the force and energy are correct.
State state = context.getState(State::Forces | State::Energy);
if (distance >= cutoff) {
ASSERT_EQUAL(0.0, state.getPotentialEnergy());
ASSERT_EQUAL_VEC(Vec3(0, 0, 0), state.getForces()[0], 0);
ASSERT_EQUAL_VEC(Vec3(0, 0, 0), state.getForces()[1], 0);
}
else {
const Vec3 force = delta*ONE_4PI_EPS0*(-1.0/(distance*distance*distance)+2.0*krf);
ASSERT_EQUAL_TOL(ONE_4PI_EPS0*(1.0/distance+krf*distance*distance-crf), state.getPotentialEnergy(), 1e-4);
ASSERT_EQUAL_VEC(force, state.getForces()[0], 1e-4);
ASSERT_EQUAL_VEC(-force, state.getForces()[1], 1e-4);
}
}
}
void testLargeSystem() {
const int numMolecules = 600;
const int numParticles = numMolecules*2;
const double cutoff = 2.0;
const double boxSize = 20.0;
const double tol = 2e-3;
ReferencePlatform reference;
System system;
for (int i = 0; i < numParticles; i++)
system.addParticle(1.0);
NonbondedForce* nonbonded = new NonbondedForce();
HarmonicBondForce* bonds = new HarmonicBondForce();
vector<Vec3> positions(numParticles);
vector<Vec3> velocities(numParticles);
OpenMM_SFMT::SFMT sfmt;
init_gen_rand(0, sfmt);
for (int i = 0; i < numMolecules; i++) {
if (i < numMolecules/2) {
nonbonded->addParticle(-1.0, 0.2, 0.1);
nonbonded->addParticle(1.0, 0.1, 0.1);
}
else {
nonbonded->addParticle(-1.0, 0.2, 0.2);
nonbonded->addParticle(1.0, 0.1, 0.2);
}
positions[2*i] = Vec3(boxSize*genrand_real2(sfmt), boxSize*genrand_real2(sfmt), boxSize*genrand_real2(sfmt));
positions[2*i+1] = Vec3(positions[2*i][0]+1.0, positions[2*i][1], positions[2*i][2]);
velocities[2*i] = Vec3(genrand_real2(sfmt), genrand_real2(sfmt), genrand_real2(sfmt));
velocities[2*i+1] = Vec3(genrand_real2(sfmt), genrand_real2(sfmt), genrand_real2(sfmt));
bonds->addBond(2*i, 2*i+1, 1.0, 0.1);
nonbonded->addException(2*i, 2*i+1, 0.0, 0.15, 0.0);
}
// Try with cutoffs but not periodic boundary conditions, and make sure it agrees with the Reference platform.
nonbonded->setNonbondedMethod(NonbondedForce::CutoffNonPeriodic);
nonbonded->setCutoffDistance(cutoff);
system.addForce(nonbonded);
system.addForce(bonds);
VerletIntegrator integrator1(0.01);
VerletIntegrator integrator2(0.01);
Context context(system, integrator1, platform);
Context referenceContext(system, integrator2, reference);
context.setPositions(positions);
context.setVelocities(velocities);
referenceContext.setPositions(positions);
referenceContext.setVelocities(velocities);
State state = context.getState(State::Positions | State::Velocities | State::Forces | State::Energy);
State referenceState = referenceContext.getState(State::Positions | State::Velocities | State::Forces | State::Energy);
for (int i = 0; i < numParticles; i++) {
ASSERT_EQUAL_VEC(state.getPositions()[i], referenceState.getPositions()[i], tol);
ASSERT_EQUAL_VEC(state.getVelocities()[i], referenceState.getVelocities()[i], tol);
ASSERT_EQUAL_VEC(state.getForces()[i], referenceState.getForces()[i], tol);
}
ASSERT_EQUAL_TOL(state.getPotentialEnergy(), referenceState.getPotentialEnergy(), tol);
// Now do the same thing with periodic boundary conditions.
nonbonded->setNonbondedMethod(NonbondedForce::CutoffPeriodic);
system.setDefaultPeriodicBoxVectors(Vec3(boxSize, 0, 0), Vec3(0, boxSize, 0), Vec3(0, 0, boxSize));
context.reinitialize();
referenceContext.reinitialize();
context.setPositions(positions);
context.setVelocities(velocities);
referenceContext.setPositions(positions);
referenceContext.setVelocities(velocities);
state = context.getState(State::Positions | State::Velocities | State::Forces | State::Energy);
referenceState = referenceContext.getState(State::Positions | State::Velocities | State::Forces | State::Energy);
for (int i = 0; i < numParticles; i++) {
double dx = state.getPositions()[i][0]-referenceState.getPositions()[i][0];
double dy = state.getPositions()[i][1]-referenceState.getPositions()[i][1];
double dz = state.getPositions()[i][2]-referenceState.getPositions()[i][2];
ASSERT_EQUAL_TOL(dx-floor(dx/boxSize+0.5)*boxSize, 0, tol);
ASSERT_EQUAL_TOL(dy-floor(dy/boxSize+0.5)*boxSize, 0, tol);
ASSERT_EQUAL_TOL(dz-floor(dz/boxSize+0.5)*boxSize, 0, tol);
ASSERT_EQUAL_VEC(state.getVelocities()[i], referenceState.getVelocities()[i], tol);
ASSERT_EQUAL_VEC(state.getForces()[i], referenceState.getForces()[i], tol);
}
ASSERT_EQUAL_TOL(state.getPotentialEnergy(), referenceState.getPotentialEnergy(), tol);
}
void testDispersionCorrection() {
// Create a box full of identical particles.
int gridSize = 5;
int numParticles = gridSize*gridSize*gridSize;
double boxSize = gridSize*0.7;
double cutoff = boxSize/3;
System system;
VerletIntegrator integrator(0.01);
NonbondedForce* nonbonded = new NonbondedForce();
vector<Vec3> positions(numParticles);
int index = 0;
for (int i = 0; i < gridSize; i++)
for (int j = 0; j < gridSize; j++)
for (int k = 0; k < gridSize; k++) {
system.addParticle(1.0);
nonbonded->addParticle(0, 1.1, 0.5);
positions[index] = Vec3(i*boxSize/gridSize, j*boxSize/gridSize, k*boxSize/gridSize);
index++;
}
nonbonded->setNonbondedMethod(NonbondedForce::CutoffPeriodic);
nonbonded->setCutoffDistance(cutoff);
system.setDefaultPeriodicBoxVectors(Vec3(boxSize, 0, 0), Vec3(0, boxSize, 0), Vec3(0, 0, boxSize));
system.addForce(nonbonded);
// See if the correction has the correct value.
Context context(system, integrator, platform);
context.setPositions(positions);
double energy1 = context.getState(State::Energy).getPotentialEnergy();
nonbonded->setUseDispersionCorrection(false);
context.reinitialize();
context.setPositions(positions);
double energy2 = context.getState(State::Energy).getPotentialEnergy();
double term1 = (0.5*pow(1.1, 12)/pow(cutoff, 9))/9;
double term2 = (0.5*pow(1.1, 6)/pow(cutoff, 3))/3;
double expected = 8*M_PI*numParticles*numParticles*(term1-term2)/(boxSize*boxSize*boxSize);
ASSERT_EQUAL_TOL(expected, energy1-energy2, 1e-4);
// Now modify half the particles to be different, and see if it is still correct.
int numType2 = 0;
for (int i = 0; i < numParticles; i += 2) {
nonbonded->setParticleParameters(i, 0, 1, 1);
numType2++;
}
int numType1 = numParticles-numType2;
nonbonded->updateParametersInContext(context);
energy2 = context.getState(State::Energy).getPotentialEnergy();
nonbonded->setUseDispersionCorrection(true);
context.reinitialize();
context.setPositions(positions);
energy1 = context.getState(State::Energy).getPotentialEnergy();
term1 = ((numType1*(numType1+1))/2)*(0.5*pow(1.1, 12)/pow(cutoff, 9))/9;
term2 = ((numType1*(numType1+1))/2)*(0.5*pow(1.1, 6)/pow(cutoff, 3))/3;
term1 += ((numType2*(numType2+1))/2)*(1*pow(1.0, 12)/pow(cutoff, 9))/9;
term2 += ((numType2*(numType2+1))/2)*(1*pow(1.0, 6)/pow(cutoff, 3))/3;
double combinedSigma = 0.5*(1+1.1);
double combinedEpsilon = sqrt(1*0.5);
term1 += (numType1*numType2)*(combinedEpsilon*pow(combinedSigma, 12)/pow(cutoff, 9))/9;
term2 += (numType1*numType2)*(combinedEpsilon*pow(combinedSigma, 6)/pow(cutoff, 3))/3;
term1 /= (numParticles*(numParticles+1))/2;
term2 /= (numParticles*(numParticles+1))/2;
expected = 8*M_PI*numParticles*numParticles*(term1-term2)/(boxSize*boxSize*boxSize);
ASSERT_EQUAL_TOL(expected, energy1-energy2, 1e-4);
}
void testChangingParameters() {
const int numMolecules = 600;
const int numParticles = numMolecules*2;
const double cutoff = 2.0;
const double boxSize = 20.0;
const double tol = 2e-3;
ReferencePlatform reference;
System system;
for (int i = 0; i < numParticles; i++)
system.addParticle(1.0);
NonbondedForce* nonbonded = new NonbondedForce();
vector<Vec3> positions(numParticles);
OpenMM_SFMT::SFMT sfmt;
init_gen_rand(0, sfmt);
for (int i = 0; i < numMolecules; i++) {
if (i < numMolecules/2) {
nonbonded->addParticle(-1.0, 0.2, 0.1);
nonbonded->addParticle(1.0, 0.1, 0.1);
}
else {
nonbonded->addParticle(-1.0, 0.2, 0.2);
nonbonded->addParticle(1.0, 0.1, 0.2);
}
positions[2*i] = Vec3(boxSize*genrand_real2(sfmt), boxSize*genrand_real2(sfmt), boxSize*genrand_real2(sfmt));
positions[2*i+1] = Vec3(positions[2*i][0]+1.0, positions[2*i][1], positions[2*i][2]);
system.addConstraint(2*i, 2*i+1, 1.0);
nonbonded->addException(2*i, 2*i+1, 0.0, 0.15, 0.0);
}
nonbonded->setNonbondedMethod(NonbondedForce::PME);
nonbonded->setCutoffDistance(cutoff);
system.addForce(nonbonded);
system.setDefaultPeriodicBoxVectors(Vec3(boxSize, 0, 0), Vec3(0, boxSize, 0), Vec3(0, 0, boxSize));
// See if the forces and energies match the Reference platform.
VerletIntegrator integrator1(0.01);
VerletIntegrator integrator2(0.01);
Context context(system, integrator1, platform);
Context referenceContext(system, integrator2, reference);
context.setPositions(positions);
referenceContext.setPositions(positions);
State state = context.getState(State::Forces | State::Energy);
State referenceState = referenceContext.getState(State::Forces | State::Energy);
for (int i = 0; i < numParticles; i++)
ASSERT_EQUAL_VEC(state.getForces()[i], referenceState.getForces()[i], tol);
ASSERT_EQUAL_TOL(state.getPotentialEnergy(), referenceState.getPotentialEnergy(), tol);
// Now modify parameters and see if they still agree.
for (int i = 0; i < numParticles; i += 5) {
double charge, sigma, epsilon;
nonbonded->getParticleParameters(i, charge, sigma, epsilon);
nonbonded->setParticleParameters(i, 1.5*charge, 1.1*sigma, 1.7*epsilon);
}
nonbonded->updateParametersInContext(context);
nonbonded->updateParametersInContext(referenceContext);
state = context.getState(State::Forces | State::Energy);
referenceState = referenceContext.getState(State::Forces | State::Energy);
for (int i = 0; i < numParticles; i++)
ASSERT_EQUAL_VEC(state.getForces()[i], referenceState.getForces()[i], tol);
ASSERT_EQUAL_TOL(state.getPotentialEnergy(), referenceState.getPotentialEnergy(), tol);
}
void testSwitchingFunction(NonbondedForce::NonbondedMethod method) {
System system;
system.setDefaultPeriodicBoxVectors(Vec3(6, 0, 0), Vec3(0, 6, 0), Vec3(0, 0, 6));
system.addParticle(1.0);
system.addParticle(1.0);
VerletIntegrator integrator(0.01);
NonbondedForce* nonbonded = new NonbondedForce();
nonbonded->addParticle(0, 1.2, 1);
nonbonded->addParticle(0, 1.4, 2);
nonbonded->setNonbondedMethod(method);
nonbonded->setCutoffDistance(2.0);
nonbonded->setUseSwitchingFunction(true);
nonbonded->setSwitchingDistance(1.5);
nonbonded->setUseDispersionCorrection(false);
system.addForce(nonbonded);
Context context(system, integrator, platform);
vector<Vec3> positions(2);
positions[0] = Vec3(0, 0, 0);
double eps = SQRT_TWO;
// Compute the interaction at various distances.
for (double r = 1.0; r < 2.5; r += 0.1) {
positions[1] = Vec3(r, 0, 0);
context.setPositions(positions);
State state = context.getState(State::Forces | State::Energy);
// See if the energy is correct.
double x = 1.3/r;
double expectedEnergy = 4.0*eps*(std::pow(x, 12.0)-std::pow(x, 6.0));
double switchValue;
if (r <= 1.5)
switchValue = 1;
else if (r >= 2.0)
switchValue = 0;
else {
double t = (r-1.5)/0.5;
switchValue = 1+t*t*t*(-10+t*(15-t*6));
}
ASSERT_EQUAL_TOL(switchValue*expectedEnergy, state.getPotentialEnergy(), TOL);
// See if the force is the gradient of the energy.
double delta = 1e-3;
positions[1] = Vec3(r-delta, 0, 0);
context.setPositions(positions);
double e1 = context.getState(State::Energy).getPotentialEnergy();
positions[1] = Vec3(r+delta, 0, 0);
context.setPositions(positions);
double e2 = context.getState(State::Energy).getPotentialEnergy();
ASSERT_EQUAL_TOL((e2-e1)/(2*delta), state.getForces()[0][0], 1e-3);
}
}
void runPlatformTests();
int main(int argc, char* argv[]) {
try {
initializeTests(argc, argv);
testCoulomb();
testLJ();
testExclusionsAnd14();
testCutoff();
testCutoff14();
testPeriodic();
testTriclinic();
testLargeSystem();
testDispersionCorrection();
testChangingParameters();
testSwitchingFunction(NonbondedForce::CutoffNonPeriodic);
testSwitchingFunction(NonbondedForce::PME);
runPlatformTests();
}
catch(const exception& e) {
cout << "exception: " << e.what() << endl;
return 1;
}
cout << "Done" << endl;
return 0;
}
tests/TestPeriodicTorsionForce.h 0 → 100644
View file @ 5e1a87fb
/* -------------------------------------------------------------------------- *
* OpenMM *
* -------------------------------------------------------------------------- *
* This is part of the OpenMM molecular simulation toolkit originating from *
* Simbios, the NIH National Center for Physics-Based Simulation of *
* Biological Structures at Stanford, funded under the NIH Roadmap for *
* Medical Research, grant U54 GM072970. See https://simtk.org. *
* *
* Portions copyright (c) 2008-2015 Stanford University and the Authors. *
* Authors: Peter Eastman *
* Contributors: *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* copy of this software and associated documentation files (the "Software"), *
* to deal in the Software without restriction, including without limitation *
* the rights to use, copy, modify, merge, publish, distribute, sublicense, *
* and/or sell copies of the Software, and to permit persons to whom the *
* Software is furnished to do so, subject to the following conditions: *
* *
* The above copyright notice and this permission notice shall be included in *
* all copies or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
* THE AUTHORS, CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE *
* USE OR OTHER DEALINGS IN THE SOFTWARE. *
* -------------------------------------------------------------------------- */
#include "openmm/internal/AssertionUtilities.h"
#include "openmm/Context.h"
#include "openmm/PeriodicTorsionForce.h"
#include "openmm/System.h"
#include "openmm/VerletIntegrator.h"
#include "SimTKOpenMMRealType.h"
#include <iostream>
#include <vector>
using namespace OpenMM;
using namespace std;
const double TOL = 1e-5;
void testPeriodicTorsions() {
System system;
system.addParticle(1.0);
system.addParticle(1.0);
system.addParticle(1.0);
system.addParticle(1.0);
VerletIntegrator integrator(0.01);
PeriodicTorsionForce* forceField = new PeriodicTorsionForce();
forceField->addTorsion(0, 1, 2, 3, 2, PI_M/3, 1.1);
system.addForce(forceField);
ASSERT(!forceField->usesPeriodicBoundaryConditions());
ASSERT(!system.usesPeriodicBoundaryConditions());
Context context(system, integrator, platform);
vector<Vec3> positions(4);
positions[0] = Vec3(0, 1, 0);
positions[1] = Vec3(0, 0, 0);
positions[2] = Vec3(1, 0, 0);
positions[3] = Vec3(1, 0, 2);
context.setPositions(positions);
State state = context.getState(State::Forces | State::Energy);
{
const vector<Vec3>& forces = state.getForces();
double torque = -2*1.1*std::sin(2*PI_M/3);
ASSERT_EQUAL_VEC(Vec3(0, 0, torque), forces[0], TOL);
ASSERT_EQUAL_VEC(Vec3(0, 0.5*torque, 0), forces[3], TOL);
ASSERT_EQUAL_VEC(Vec3(forces[0][0]+forces[1][0]+forces[2][0]+forces[3][0], forces[0][1]+forces[1][1]+forces[2][1]+forces[3][1], forces[0][2]+forces[1][2]+forces[2][2]+forces[3][2]), Vec3(0, 0, 0), TOL);
ASSERT_EQUAL_TOL(1.1*(1+std::cos(2*PI_M/3)), state.getPotentialEnergy(), TOL);
}
// Try changing the torsion parameters and make sure it's still correct.
forceField->setTorsionParameters(0, 0, 1, 2, 3, 3, PI_M/3.2, 1.3);
forceField->updateParametersInContext(context);
state = context.getState(State::Forces | State::Energy);
{
const vector<Vec3>& forces = state.getForces();
double dtheta = (3*PI_M/2)-(PI_M/3.2);
double torque = -3*1.3*std::sin(dtheta);
ASSERT_EQUAL_VEC(Vec3(0, 0, torque), forces[0], TOL);
ASSERT_EQUAL_VEC(Vec3(0, 0.5*torque, 0), forces[3], TOL);
ASSERT_EQUAL_VEC(Vec3(forces[0][0]+forces[1][0]+forces[2][0]+forces[3][0], forces[0][1]+forces[1][1]+forces[2][1]+forces[3][1], forces[0][2]+forces[1][2]+forces[2][2]+forces[3][2]), Vec3(0, 0, 0), TOL);
ASSERT_EQUAL_TOL(1.3*(1+std::cos(dtheta)), state.getPotentialEnergy(), TOL);
}
}
void runPlatformTests();
int main(int argc, char* argv[]) {
try {
initializeTests(argc, argv);
testPeriodicTorsions();
runPlatformTests();
}
catch(const exception& e) {
cout << "exception: " << e.what() << endl;
return 1;
}
cout << "Done" << endl;
return 0;
}
tests/TestRBTorsionForce.h 0 → 100644
View file @ 5e1a87fb
/* -------------------------------------------------------------------------- *
* OpenMM *
* -------------------------------------------------------------------------- *
* This is part of the OpenMM molecular simulation toolkit originating from *
* Simbios, the NIH National Center for Physics-Based Simulation of *
* Biological Structures at Stanford, funded under the NIH Roadmap for *
* Medical Research, grant U54 GM072970. See https://simtk.org. *
* *
* Portions copyright (c) 2008-2015 Stanford University and the Authors. *
* Authors: Peter Eastman *
* Contributors: *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* copy of this software and associated documentation files (the "Software"), *
* to deal in the Software without restriction, including without limitation *
* the rights to use, copy, modify, merge, publish, distribute, sublicense, *
* and/or sell copies of the Software, and to permit persons to whom the *
* Software is furnished to do so, subject to the following conditions: *
* *
* The above copyright notice and this permission notice shall be included in *
* all copies or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
* THE AUTHORS, CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE *
* USE OR OTHER DEALINGS IN THE SOFTWARE. *
* -------------------------------------------------------------------------- */
#include "openmm/internal/AssertionUtilities.h"
#include "openmm/Context.h"
#include "openmm/RBTorsionForce.h"
#include "openmm/System.h"
#include "openmm/VerletIntegrator.h"
#include "SimTKOpenMMRealType.h"
#include <iostream>
#include <vector>
using namespace OpenMM;
using namespace std;
const double TOL = 1e-5;
void testRBTorsions() {
System system;
system.addParticle(1.0);
system.addParticle(1.0);
system.addParticle(1.0);
system.addParticle(1.0);
VerletIntegrator integrator(0.01);
RBTorsionForce* forceField = new RBTorsionForce();
forceField->addTorsion(0, 1, 2, 3, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6);
system.addForce(forceField);
ASSERT(!forceField->usesPeriodicBoundaryConditions());
ASSERT(!system.usesPeriodicBoundaryConditions());
Context context(system, integrator, platform);
vector<Vec3> positions(4);
positions[0] = Vec3(0, 1, 0);
positions[1] = Vec3(0, 0, 0);
positions[2] = Vec3(1, 0, 0);
positions[3] = Vec3(1, 1, 1);
context.setPositions(positions);
State state = context.getState(State::Forces | State::Energy);
{
const vector<Vec3>& forces = state.getForces();
double psi = 0.25*PI_M - PI_M;
double torque = 0.0;
for (int i = 1; i < 6; ++i) {
double c = 0.1*(i+1);
torque += -c*i*std::pow(std::cos(psi), i-1)*std::sin(psi);
}
ASSERT_EQUAL_VEC(Vec3(0, 0, torque), forces[0], TOL);
ASSERT_EQUAL_VEC(Vec3(0, 0.5*torque, -0.5*torque), forces[3], TOL);
ASSERT_EQUAL_VEC(Vec3(forces[0][0]+forces[1][0]+forces[2][0]+forces[3][0], forces[0][1]+forces[1][1]+forces[2][1]+forces[3][1], forces[0][2]+forces[1][2]+forces[2][2]+forces[3][2]), Vec3(0, 0, 0), TOL);
double energy = 0.0;
for (int i = 0; i < 6; ++i) {
double c = 0.1*(i+1);
energy += c*std::pow(std::cos(psi), i);
}
ASSERT_EQUAL_TOL(energy, state.getPotentialEnergy(), TOL);
}
// Try changing the torsion parameters and make sure it's still correct.
forceField->setTorsionParameters(0, 0, 1, 2, 3, 0.11, 0.22, 0.33, 0.44, 0.55, 0.66);
forceField->updateParametersInContext(context);
state = context.getState(State::Forces | State::Energy);
{
const vector<Vec3>& forces = state.getForces();
double psi = 0.25*PI_M - PI_M;
double torque = 0.0;
for (int i = 1; i < 6; ++i) {
double c = 0.11*(i+1);
torque += -c*i*std::pow(std::cos(psi), i-1)*std::sin(psi);
}
ASSERT_EQUAL_VEC(Vec3(0, 0, torque), forces[0], TOL);
ASSERT_EQUAL_VEC(Vec3(0, 0.5*torque, -0.5*torque), forces[3], TOL);
ASSERT_EQUAL_VEC(Vec3(forces[0][0]+forces[1][0]+forces[2][0]+forces[3][0], forces[0][1]+forces[1][1]+forces[2][1]+forces[3][1], forces[0][2]+forces[1][2]+forces[2][2]+forces[3][2]), Vec3(0, 0, 0), TOL);
double energy = 0.0;
for (int i = 0; i < 6; ++i) {
double c = 0.11*(i+1);
energy += c*std::pow(std::cos(psi), i);
}
ASSERT_EQUAL_TOL(energy, state.getPotentialEnergy(), TOL);
}
}
void runPlatformTests();
int main(int argc, char* argv[]) {
try {
initializeTests(argc, argv);
testRBTorsions();
runPlatformTests();
}
catch(const exception& e) {
cout << "exception: " << e.what() << endl;
return 1;
}
cout << "Done" << endl;
return 0;
}
tests/TestSettle.h 0 → 100644
View file @ 5e1a87fb
/* -------------------------------------------------------------------------- *
* OpenMM *
* -------------------------------------------------------------------------- *
* This is part of the OpenMM molecular simulation toolkit originating from *
* Simbios, the NIH National Center for Physics-Based Simulation of *
* Biological Structures at Stanford, funded under the NIH Roadmap for *
* Medical Research, grant U54 GM072970. See https://simtk.org. *
* *
* Portions copyright (c) 2008-2015 Stanford University and the Authors. *
* Authors: Peter Eastman *
* Contributors: *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* copy of this software and associated documentation files (the "Software"), *
* to deal in the Software without restriction, including without limitation *
* the rights to use, copy, modify, merge, publish, distribute, sublicense, *
* and/or sell copies of the Software, and to permit persons to whom the *
* Software is furnished to do so, subject to the following conditions: *
* *
* The above copyright notice and this permission notice shall be included in *
* all copies or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
* THE AUTHORS, CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE *
* USE OR OTHER DEALINGS IN THE SOFTWARE. *
* -------------------------------------------------------------------------- */
#include "openmm/internal/AssertionUtilities.h"
#include "openmm/Context.h"
#include "openmm/NonbondedForce.h"
#include "openmm/System.h"
#include "openmm/LangevinIntegrator.h"
#include "sfmt/SFMT.h"
#include <iostream>
#include <vector>
using namespace OpenMM;
using namespace std;
void testConstraints() {
const int numMolecules = 10;
const int numParticles = numMolecules*3;
const int numConstraints = numMolecules*3;
const double temp = 100.0;
System system;
LangevinIntegrator integrator(temp, 2.0, 0.001);
integrator.setConstraintTolerance(1e-5);
NonbondedForce* forceField = new NonbondedForce();
for (int i = 0; i < numMolecules; ++i) {
system.addParticle(16.0);
system.addParticle(1.0);
system.addParticle(1.0);
forceField->addParticle(-0.82, 0.317, 0.65);
forceField->addParticle(0.41, 1.0, 0.0);
forceField->addParticle(0.41, 1.0, 0.0);
system.addConstraint(i*3, i*3+1, 0.1);
system.addConstraint(i*3, i*3+2, 0.1);
system.addConstraint(i*3+1, i*3+2, 0.163);
}
system.addForce(forceField);
Context context(system, integrator, platform);
vector<Vec3> positions(numParticles);
vector<Vec3> velocities(numParticles);
OpenMM_SFMT::SFMT sfmt;
init_gen_rand(0, sfmt);
for (int i = 0; i < numMolecules; ++i) {
positions[i*3] = Vec3((i%4)*0.4, (i/4)*0.4, 0);
positions[i*3+1] = positions[i*3]+Vec3(0.1, 0, 0);
positions[i*3+2] = positions[i*3]+Vec3(-0.03333, 0.09428, 0);
velocities[i*3] = Vec3(genrand_real2(sfmt)-0.5, genrand_real2(sfmt)-0.5, genrand_real2(sfmt)-0.5);
velocities[i*3+1] = Vec3(genrand_real2(sfmt)-0.5, genrand_real2(sfmt)-0.5, genrand_real2(sfmt)-0.5);
velocities[i*3+2] = Vec3(genrand_real2(sfmt)-0.5, genrand_real2(sfmt)-0.5, genrand_real2(sfmt)-0.5);
}
context.setPositions(positions);
context.setVelocities(velocities);
// Simulate it and see whether the constraints remain satisfied.
for (int i = 0; i < 1000; ++i) {
integrator.step(1);
State state = context.getState(State::Positions | State::Forces);
for (int j = 0; j < numConstraints; ++j) {
int particle1, particle2;
double distance;
system.getConstraintParameters(j, particle1, particle2, distance);
Vec3 p1 = state.getPositions()[particle1];
Vec3 p2 = state.getPositions()[particle2];
double dist = std::sqrt((p1[0]-p2[0])*(p1[0]-p2[0])+(p1[1]-p2[1])*(p1[1]-p2[1])+(p1[2]-p2[2])*(p1[2]-p2[2]));
ASSERT_EQUAL_TOL(distance, dist, 1e-5);
}
}
}
void runPlatformTests();
int main(int argc, char* argv[]) {
try {
initializeTests(argc, argv);
testConstraints();
runPlatformTests();
}
catch(const exception& e) {
cout << "exception: " << e.what() << endl;
return 1;
}
cout << "Done" << endl;
return 0;
}
tests/TestVariableLangevinIntegrator.h 0 → 100644
View file @ 5e1a87fb
/* -------------------------------------------------------------------------- *
* OpenMM *
* -------------------------------------------------------------------------- *
* This is part of the OpenMM molecular simulation toolkit originating from *
* Simbios, the NIH National Center for Physics-Based Simulation of *
* Biological Structures at Stanford, funded under the NIH Roadmap for *
* Medical Research, grant U54 GM072970. See https://simtk.org. *
* *
* Portions copyright (c) 2008-2015 Stanford University and the Authors. *
* Authors: Peter Eastman *
* Contributors: *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* copy of this software and associated documentation files (the "Software"), *
* to deal in the Software without restriction, including without limitation *
* the rights to use, copy, modify, merge, publish, distribute, sublicense, *
* and/or sell copies of the Software, and to permit persons to whom the *
* Software is furnished to do so, subject to the following conditions: *
* *
* The above copyright notice and this permission notice shall be included in *
* all copies or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
* THE AUTHORS, CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE *
* USE OR OTHER DEALINGS IN THE SOFTWARE. *
* -------------------------------------------------------------------------- */
#include "openmm/internal/AssertionUtilities.h"
#include "openmm/Context.h"
#include "openmm/HarmonicBondForce.h"
#include "openmm/NonbondedForce.h"
#include "openmm/System.h"
#include "openmm/VariableLangevinIntegrator.h"
#include "SimTKOpenMMRealType.h"
#include "sfmt/SFMT.h"
#include <iostream>
#include <vector>
using namespace OpenMM;
using namespace std;
const double TOL = 1e-5;
void testSingleBond() {
System system;
system.addParticle(2.0);
system.addParticle(2.0);
VariableLangevinIntegrator integrator(0, 0.1, 1e-6);
HarmonicBondForce* forceField = new HarmonicBondForce();
forceField->addBond(0, 1, 1.5, 1);
system.addForce(forceField);
Context context(system, integrator, platform);
vector<Vec3> positions(2);
positions[0] = Vec3(-1, 0, 0);
positions[1] = Vec3(1, 0, 0);
context.setPositions(positions);
// This is simply a damped harmonic oscillator, so compare it to the analytical solution.
double freq = std::sqrt(1-0.05*0.05);
for (int i = 0; i < 1000; ++i) {
State state = context.getState(State::Positions | State::Velocities);
double time = state.getTime();
double expectedDist = 1.5+0.5*std::exp(-0.05*time)*std::cos(freq*time);
ASSERT_EQUAL_VEC(Vec3(-0.5*expectedDist, 0, 0), state.getPositions()[0], 0.02);
ASSERT_EQUAL_VEC(Vec3(0.5*expectedDist, 0, 0), state.getPositions()[1], 0.02);
double expectedSpeed = -0.5*std::exp(-0.05*time)*(0.05*std::cos(freq*time)+freq*std::sin(freq*time));
ASSERT_EQUAL_VEC(Vec3(-0.5*expectedSpeed, 0, 0), state.getVelocities()[0], 0.02);
ASSERT_EQUAL_VEC(Vec3(0.5*expectedSpeed, 0, 0), state.getVelocities()[1], 0.02);
integrator.step(1);
}
// Now set the friction to a tiny value and see if it conserves energy.
integrator.setFriction(5e-5);
context.setPositions(positions);
State state = context.getState(State::Energy);
double initialEnergy = state.getKineticEnergy()+state.getPotentialEnergy();
for (int i = 0; i < 1000; ++i) {
state = context.getState(State::Energy);
double energy = state.getKineticEnergy()+state.getPotentialEnergy();
ASSERT_EQUAL_TOL(initialEnergy, energy, 0.05);
integrator.step(1);
}
}
void testTemperature() {
const int numParticles = 8;
const double temp = 100.0;
System system;
VariableLangevinIntegrator integrator(temp, 5.0, 5e-5);
NonbondedForce* forceField = new NonbondedForce();
for (int i = 0; i < numParticles; ++i) {
system.addParticle(2.0);
forceField->addParticle((i%2 == 0 ? 1.0 : -1.0), 1.0, 5.0);
}
system.addForce(forceField);
Context context(system, integrator, platform);
vector<Vec3> positions(numParticles);
for (int i = 0; i < numParticles; ++i)
positions[i] = Vec3((i%2 == 0 ? 2 : -2), (i%4 < 2 ? 2 : -2), (i < 4 ? 2 : -2));
context.setPositions(positions);
context.setVelocitiesToTemperature(temp);
// Let it equilibrate.
integrator.step(5000);
// Now run it for a while and see if the temperature is correct.
double ke = 0.0;
for (int i = 0; i < 5000; ++i) {
State state = context.getState(State::Energy);
ke += state.getKineticEnergy();
integrator.step(5);
}
ke /= 5000;
double expected = 0.5*numParticles*3*BOLTZ*temp;
ASSERT_USUALLY_EQUAL_TOL(expected, ke, 0.1);
}
void testConstraints() {
const int numParticles = 8;
const double temp = 100.0;
System system;
VariableLangevinIntegrator integrator(temp, 2.0, 1e-5);
integrator.setConstraintTolerance(1e-5);
integrator.setRandomNumberSeed(0);
NonbondedForce* forceField = new NonbondedForce();
for (int i = 0; i < numParticles; ++i) {
system.addParticle(10.0);
forceField->addParticle((i%2 == 0 ? 0.2 : -0.2), 0.5, 5.0);
}
for (int i = 0; i < numParticles-1; ++i)
system.addConstraint(i, i+1, 1.0);
system.addForce(forceField);
Context context(system, integrator, platform);
vector<Vec3> positions(numParticles);
vector<Vec3> velocities(numParticles);
OpenMM_SFMT::SFMT sfmt;
init_gen_rand(0, sfmt);
for (int i = 0; i < numParticles; ++i) {
positions[i] = Vec3(i/2, (i+1)/2, 0);
velocities[i] = Vec3(genrand_real2(sfmt)-0.5, genrand_real2(sfmt)-0.5, genrand_real2(sfmt)-0.5);
}
context.setPositions(positions);
context.setVelocities(velocities);
// Simulate it and see whether the constraints remain satisfied.
for (int i = 0; i < 1000; ++i) {
State state = context.getState(State::Positions);
for (int j = 0; j < numParticles-1; ++j) {
Vec3 p1 = state.getPositions()[j];
Vec3 p2 = state.getPositions()[j+1];
double dist = std::sqrt((p1[0]-p2[0])*(p1[0]-p2[0])+(p1[1]-p2[1])*(p1[1]-p2[1])+(p1[2]-p2[2])*(p1[2]-p2[2]));
ASSERT_EQUAL_TOL(1.0, dist, 2e-5);
}
integrator.step(1);
}
}
void testConstrainedMasslessParticles() {
System system;
system.addParticle(0.0);
system.addParticle(1.0);
system.addConstraint(0, 1, 1.5);
vector<Vec3> positions(2);
positions[0] = Vec3(-1, 0, 0);
positions[1] = Vec3(1, 0, 0);
VariableLangevinIntegrator integrator(300.0, 2.0, 0.01);
bool failed = false;
try {
// This should throw an exception.
Context context(system, integrator, platform);
}
catch (exception& ex) {
failed = true;
}
ASSERT(failed);
// Now make both particles massless, which should work.
system.setParticleMass(1, 0.0);
Context context(system, integrator, platform);
context.setPositions(positions);
context.setVelocitiesToTemperature(300.0);
integrator.step(1);
State state = context.getState(State::Velocities);
ASSERT_EQUAL(0.0, state.getVelocities()[0][0]);
}
void testRandomSeed() {
const int numParticles = 8;
const double temp = 100.0;
System system;
VariableLangevinIntegrator integrator(temp, 2.0, 1e-5);
NonbondedForce* forceField = new NonbondedForce();
for (int i = 0; i < numParticles; ++i) {
system.addParticle(2.0);
forceField->addParticle((i%2 == 0 ? 1.0 : -1.0), 1.0, 5.0);
}
system.addForce(forceField);
vector<Vec3> positions(numParticles);
vector<Vec3> velocities(numParticles);
for (int i = 0; i < numParticles; ++i) {
positions[i] = Vec3((i%2 == 0 ? 2 : -2), (i%4 < 2 ? 2 : -2), (i < 4 ? 2 : -2));
velocities[i] = Vec3(0, 0, 0);
}
// Try twice with the same random seed.
integrator.setRandomNumberSeed(5);
Context context(system, integrator, platform);
context.setPositions(positions);
context.setVelocities(velocities);
integrator.step(10);
State state1 = context.getState(State::Positions);
context.reinitialize();
context.setPositions(positions);
context.setVelocities(velocities);
integrator.step(10);
State state2 = context.getState(State::Positions);
// Try twice with a different random seed.
integrator.setRandomNumberSeed(10);
context.reinitialize();
context.setPositions(positions);
context.setVelocities(velocities);
integrator.step(10);
State state3 = context.getState(State::Positions);
context.reinitialize();
context.setPositions(positions);
context.setVelocities(velocities);
integrator.step(10);
State state4 = context.getState(State::Positions);
// Compare the results.
for (int i = 0; i < numParticles; i++) {
for (int j = 0; j < 3; j++) {
ASSERT(state1.getPositions()[i][j] == state2.getPositions()[i][j]);
ASSERT(state3.getPositions()[i][j] == state4.getPositions()[i][j]);
ASSERT(state1.getPositions()[i][j] != state3.getPositions()[i][j]);
}
}
}
void testArgonBox() {
const int gridSize = 8;
const double mass = 40.0; // Ar atomic mass
const double temp = 120.0; // K
const double epsilon = BOLTZ * temp; // L-J well depth for Ar
const double sigma = 0.34; // L-J size for Ar in nm
const double density = 0.8; // atoms / sigma^3
double cellSize = sigma / pow(density, 0.333);
double boxSize = gridSize * cellSize;
double cutoff = 2.0 * sigma;
// Create a box of argon atoms.
System system;
NonbondedForce* nonbonded = new NonbondedForce();
vector<Vec3> positions;
OpenMM_SFMT::SFMT sfmt;
init_gen_rand(0, sfmt);
const Vec3 half(0.5, 0.5, 0.5);
int numParticles = 0;
for (int i = 0; i < gridSize; i++) {
for (int j = 0; j < gridSize; j++) {
for (int k = 0; k < gridSize; k++) {
system.addParticle(mass);
nonbonded->addParticle(0, sigma, epsilon);
positions.push_back((Vec3(i, j, k) + half + Vec3(genrand_real2(sfmt), genrand_real2(sfmt), genrand_real2(sfmt))*0.1) * cellSize);
++numParticles;
}
}
}
nonbonded->setNonbondedMethod(NonbondedForce::CutoffPeriodic);
nonbonded->setCutoffDistance(cutoff);
system.setDefaultPeriodicBoxVectors(Vec3(boxSize, 0, 0), Vec3(0, boxSize, 0), Vec3(0, 0, boxSize));
system.addForce(nonbonded);
VariableLangevinIntegrator integrator(temp, 6.0, 1e-4);
Context context(system, integrator, platform);
context.setPositions(positions);
context.setVelocitiesToTemperature(temp);
// Equilibrate.
integrator.stepTo(2.0);
// Make sure the temperature is correct.
double ke = 0.0;
for (int i = 0; i < 1000; ++i) {
double t = 2.0 + 0.02 * (i + 1);
integrator.stepTo(t);
State state = context.getState(State::Energy);
ke += state.getKineticEnergy();
}
ke /= 1000;
double expected = 1.5 * numParticles * BOLTZ * temp;
ASSERT_USUALLY_EQUAL_TOL(expected, ke, 0.01);
}
void runPlatformTests();
int main(int argc, char* argv[]) {
try {
initializeTests(argc, argv);
testSingleBond();
testTemperature();
testConstraints();
testConstrainedMasslessParticles();
testRandomSeed();
testArgonBox();
runPlatformTests();
}
catch(const exception& e) {
cout << "exception: " << e.what() << endl;
return 1;
}
cout << "Done" << endl;
return 0;
}
tests/TestVariableVerletIntegrator.h 0 → 100644
View file @ 5e1a87fb
/* -------------------------------------------------------------------------- *
* OpenMM *
* -------------------------------------------------------------------------- *
* This is part of the OpenMM molecular simulation toolkit originating from *
* Simbios, the NIH National Center for Physics-Based Simulation of *
* Biological Structures at Stanford, funded under the NIH Roadmap for *
* Medical Research, grant U54 GM072970. See https://simtk.org. *
* *
* Portions copyright (c) 2008-2015 Stanford University and the Authors. *
* Authors: Peter Eastman *
* Contributors: *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* copy of this software and associated documentation files (the "Software"), *
* to deal in the Software without restriction, including without limitation *
* the rights to use, copy, modify, merge, publish, distribute, sublicense, *
* and/or sell copies of the Software, and to permit persons to whom the *
* Software is furnished to do so, subject to the following conditions: *
* *
* The above copyright notice and this permission notice shall be included in *
* all copies or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
* THE AUTHORS, CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE *
* USE OR OTHER DEALINGS IN THE SOFTWARE. *
* -------------------------------------------------------------------------- */
#include "openmm/internal/AssertionUtilities.h"
#include "openmm/Context.h"
#include "openmm/HarmonicBondForce.h"
#include "openmm/NonbondedForce.h"
#include "openmm/System.h"
#include "openmm/VariableVerletIntegrator.h"
#include "SimTKOpenMMRealType.h"
#include "sfmt/SFMT.h"
#include <iostream>
#include <vector>
using namespace OpenMM;
using namespace std;
const double TOL = 1e-5;
void testSingleBond() {
System system;
system.addParticle(2.0);
system.addParticle(2.0);
VariableVerletIntegrator integrator(1e-6);
HarmonicBondForce* forceField = new HarmonicBondForce();
forceField->addBond(0, 1, 1.5, 1);
system.addForce(forceField);
Context context(system, integrator, platform);
vector<Vec3> positions(2);
positions[0] = Vec3(-1, 0, 0);
positions[1] = Vec3(1, 0, 0);
context.setPositions(positions);
// This is simply a harmonic oscillator, so compare it to the analytical solution.
const double freq = 1.0;
State state = context.getState(State::Energy);
const double initialEnergy = state.getKineticEnergy()+state.getPotentialEnergy();
for (int i = 0; i < 1000; ++i) {
state = context.getState(State::Positions | State::Velocities | State::Energy);
double time = state.getTime();
double expectedDist = 1.5+0.5*std::cos(freq*time);
ASSERT_EQUAL_VEC(Vec3(-0.5*expectedDist, 0, 0), state.getPositions()[0], 0.02);
ASSERT_EQUAL_VEC(Vec3(0.5*expectedDist, 0, 0), state.getPositions()[1], 0.02);
double expectedSpeed = -0.5*freq*std::sin(freq*time);
ASSERT_EQUAL_VEC(Vec3(-0.5*expectedSpeed, 0, 0), state.getVelocities()[0], 0.02);
ASSERT_EQUAL_VEC(Vec3(0.5*expectedSpeed, 0, 0), state.getVelocities()[1], 0.02);
double energy = state.getKineticEnergy()+state.getPotentialEnergy();
ASSERT_EQUAL_TOL(initialEnergy, energy, 0.05);
integrator.step(1);
}
ASSERT(state.getTime() > 1.0);
}
void testConstraints() {
const int numParticles = 8;
const int numConstraints = 5;
System system;
VariableVerletIntegrator integrator(1e-5);
integrator.setConstraintTolerance(1e-5);
NonbondedForce* forceField = new NonbondedForce();
for (int i = 0; i < numParticles; ++i) {
system.addParticle(i%2 == 0 ? 5.0 : 10.0);
forceField->addParticle((i%2 == 0 ? 0.2 : -0.2), 0.5, 5.0);
}
system.addConstraint(0, 1, 1.0);
system.addConstraint(1, 2, 1.0);
system.addConstraint(2, 3, 1.0);
system.addConstraint(4, 5, 1.0);
system.addConstraint(6, 7, 1.0);
system.addForce(forceField);
Context context(system, integrator, platform);
vector<Vec3> positions(numParticles);
vector<Vec3> velocities(numParticles);
OpenMM_SFMT::SFMT sfmt;
init_gen_rand(0, sfmt);
for (int i = 0; i < numParticles; ++i) {
positions[i] = Vec3(i/2, (i+1)/2, 0);
velocities[i] = Vec3(genrand_real2(sfmt)-0.5, genrand_real2(sfmt)-0.5, genrand_real2(sfmt)-0.5);
}
context.setPositions(positions);
context.setVelocities(velocities);
// Simulate it and see whether the constraints remain satisfied.
double initialEnergy = 0.0;
for (int i = 0; i < 1000; ++i) {
State state = context.getState(State::Positions | State::Energy | State::Velocities | State::Forces);
for (int j = 0; j < numConstraints; ++j) {
int particle1, particle2;
double distance;
system.getConstraintParameters(j, particle1, particle2, distance);
Vec3 p1 = state.getPositions()[particle1];
Vec3 p2 = state.getPositions()[particle2];
double dist = std::sqrt((p1[0]-p2[0])*(p1[0]-p2[0])+(p1[1]-p2[1])*(p1[1]-p2[1])+(p1[2]-p2[2])*(p1[2]-p2[2]));
ASSERT_EQUAL_TOL(distance, dist, 1e-4);
}
double energy = state.getKineticEnergy()+state.getPotentialEnergy();
if (i == 1)
initialEnergy = energy;
else if (i > 1)
ASSERT_EQUAL_TOL(initialEnergy, energy, 0.01);
integrator.step(1);
}
double finalTime = context.getState(State::Positions).getTime();
ASSERT(finalTime > 0.1);
// Now try the stepTo() method.
finalTime += 0.5;
integrator.stepTo(finalTime);
ASSERT_EQUAL(finalTime, context.getState(State::Positions).getTime());
}
void testConstrainedClusters() {
const int numParticles = 7;
System system;
VariableVerletIntegrator integrator(1e-5);
integrator.setConstraintTolerance(1e-5);
NonbondedForce* forceField = new NonbondedForce();
for (int i = 0; i < numParticles; ++i) {
system.addParticle(i > 1 ? 1.0 : 10.0);
forceField->addParticle((i%2 == 0 ? 0.2 : -0.2), 0.5, 5.0);
}
system.addConstraint(0, 1, 1.0);
system.addConstraint(0, 2, 1.0);
system.addConstraint(0, 3, 1.0);
system.addConstraint(0, 4, 1.0);
system.addConstraint(1, 5, 1.0);
system.addConstraint(1, 6, 1.0);
system.addConstraint(2, 3, sqrt(2.0));
system.addConstraint(2, 4, sqrt(2.0));
system.addConstraint(3, 4, sqrt(2.0));
system.addConstraint(5, 6, sqrt(2.0));
system.addForce(forceField);
Context context(system, integrator, platform);
vector<Vec3> positions(numParticles);
positions[0] = Vec3(0, 0, 0);
positions[1] = Vec3(1, 0, 0);
positions[2] = Vec3(-1, 0, 0);
positions[3] = Vec3(0, 1, 0);
positions[4] = Vec3(0, 0, 1);
positions[5] = Vec3(2, 0, 0);
positions[6] = Vec3(1, 1, 0);
vector<Vec3> velocities(numParticles);
OpenMM_SFMT::SFMT sfmt;
init_gen_rand(0, sfmt);
for (int i = 0; i < numParticles; ++i)
velocities[i] = Vec3(genrand_real2(sfmt)-0.5, genrand_real2(sfmt)-0.5, genrand_real2(sfmt)-0.5);
context.setPositions(positions);
context.setVelocities(velocities);
// Simulate it and see whether the constraints remain satisfied.
double initialEnergy = 0.0;
for (int i = 0; i < 1000; ++i) {
State state = context.getState(State::Positions | State::Energy | State::Velocities | State::Forces);
for (int j = 0; j < system.getNumConstraints(); ++j) {
int particle1, particle2;
double distance;
system.getConstraintParameters(j, particle1, particle2, distance);
Vec3 p1 = state.getPositions()[particle1];
Vec3 p2 = state.getPositions()[particle2];
double dist = std::sqrt((p1[0]-p2[0])*(p1[0]-p2[0])+(p1[1]-p2[1])*(p1[1]-p2[1])+(p1[2]-p2[2])*(p1[2]-p2[2]));
ASSERT_EQUAL_TOL(distance, dist, 2e-5);
}
double energy = state.getKineticEnergy()+state.getPotentialEnergy();
if (i == 1)
initialEnergy = energy;
else if (i > 1)
ASSERT_EQUAL_TOL(initialEnergy, energy, 0.01);
integrator.step(1);
}
ASSERT(context.getState(State::Positions).getTime() > 0.1);
}
void testConstrainedMasslessParticles() {
System system;
system.addParticle(0.0);
system.addParticle(1.0);
system.addConstraint(0, 1, 1.5);
vector<Vec3> positions(2);
positions[0] = Vec3(-1, 0, 0);
positions[1] = Vec3(1, 0, 0);
VariableVerletIntegrator integrator(0.01);
bool failed = false;
try {
// This should throw an exception.
Context context(system, integrator, platform);
}
catch (exception& ex) {
failed = true;
}
ASSERT(failed);
// Now make both particles massless, which should work.
system.setParticleMass(1, 0.0);
Context context(system, integrator, platform);
context.setPositions(positions);
context.setVelocitiesToTemperature(300.0);
integrator.step(1);
State state = context.getState(State::Velocities);
ASSERT_EQUAL(0.0, state.getVelocities()[0][0]);
}
void testArgonBox() {
const int gridSize = 8;
const double mass = 40.0; // Ar atomic mass
const double temp = 120.0; // K
const double epsilon = BOLTZ * temp; // L-J well depth for Ar
const double sigma = 0.34; // L-J size for Ar in nm
const double density = 0.8; // atoms / sigma^3
double cellSize = sigma / pow(density, 0.333);
double boxSize = gridSize * cellSize;
double cutoff = 2.0 * sigma;
// Create a box of argon atoms.
System system;
NonbondedForce* nonbonded = new NonbondedForce();
vector<Vec3> positions;
OpenMM_SFMT::SFMT sfmt;
init_gen_rand(0, sfmt);
const Vec3 half(0.5, 0.5, 0.5);
for (int i = 0; i < gridSize; i++) {
for (int j = 0; j < gridSize; j++) {
for (int k = 0; k < gridSize; k++) {
system.addParticle(mass);
nonbonded->addParticle(0, sigma, epsilon);
positions.push_back((Vec3(i, j, k) + half + Vec3(genrand_real2(sfmt), genrand_real2(sfmt), genrand_real2(sfmt))*0.1) * cellSize);
}
}
}
nonbonded->setNonbondedMethod(NonbondedForce::CutoffPeriodic);
nonbonded->setCutoffDistance(cutoff);
system.setDefaultPeriodicBoxVectors(Vec3(boxSize, 0, 0), Vec3(0, boxSize, 0), Vec3(0, 0, boxSize));
system.addForce(nonbonded);
VariableVerletIntegrator integrator(1e-5);
Context context(system, integrator, platform);
context.setPositions(positions);
context.setVelocitiesToTemperature(temp);
// Equilibrate.
integrator.stepTo(1.0);
// Simulate it and see whether energy remains constant.
State state0 = context.getState(State::Energy);
double initialEnergy = state0.getKineticEnergy() + state0.getPotentialEnergy();
for (int i = 0; i < 20; i++) {
double t = 1.0 + 0.05*(i+1);
integrator.stepTo(t);
State state = context.getState(State::Energy);
double energy = state.getKineticEnergy() + state.getPotentialEnergy();
ASSERT_EQUAL_TOL(initialEnergy, energy, 0.01);
}
}
void runPlatformTests();
int main(int argc, char* argv[]) {
try {
initializeTests(argc, argv);
testSingleBond();
testConstraints();
testConstrainedClusters();
testConstrainedMasslessParticles();
testArgonBox();
runPlatformTests();
}
catch(const exception& e) {
cout << "exception: " << e.what() << endl;
return 1;
}
cout << "Done" << endl;
return 0;
}
tests/TestVerletIntegrator.h 0 → 100644
View file @ 5e1a87fb
/* -------------------------------------------------------------------------- *
* OpenMM *
* -------------------------------------------------------------------------- *
* This is part of the OpenMM molecular simulation toolkit originating from *
* Simbios, the NIH National Center for Physics-Based Simulation of *
* Biological Structures at Stanford, funded under the NIH Roadmap for *
* Medical Research, grant U54 GM072970. See https://simtk.org. *
* *
* Portions copyright (c) 2008-2015 Stanford University and the Authors. *
* Authors: Peter Eastman *
* Contributors: *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* copy of this software and associated documentation files (the "Software"), *
* to deal in the Software without restriction, including without limitation *
* the rights to use, copy, modify, merge, publish, distribute, sublicense, *
* and/or sell copies of the Software, and to permit persons to whom the *
* Software is furnished to do so, subject to the following conditions: *
* *
* The above copyright notice and this permission notice shall be included in *
* all copies or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
* THE AUTHORS, CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE *
* USE OR OTHER DEALINGS IN THE SOFTWARE. *
* -------------------------------------------------------------------------- */
#include "openmm/internal/AssertionUtilities.h"
#include "openmm/Context.h"
#include "openmm/HarmonicBondForce.h"
#include "openmm/NonbondedForce.h"
#include "openmm/System.h"
#include "openmm/VerletIntegrator.h"
#include "SimTKOpenMMRealType.h"
#include "sfmt/SFMT.h"
#include <iostream>
#include <vector>
using namespace OpenMM;
using namespace std;
const double TOL = 1e-5;
void testSingleBond() {
System system;
system.addParticle(2.0);
system.addParticle(2.0);
VerletIntegrator integrator(0.01);
HarmonicBondForce* forceField = new HarmonicBondForce();
forceField->addBond(0, 1, 1.5, 1);
system.addForce(forceField);
Context context(system, integrator, platform);
vector<Vec3> positions(2);
positions[0] = Vec3(-1, 0, 0);
positions[1] = Vec3(1, 0, 0);
context.setPositions(positions);
// This is simply a harmonic oscillator, so compare it to the analytical solution.
const double freq = 1.0;
State state = context.getState(State::Energy);
const double initialEnergy = state.getKineticEnergy()+state.getPotentialEnergy();
for (int i = 0; i < 1000; ++i) {
state = context.getState(State::Positions | State::Velocities | State::Energy);
double time = state.getTime();
double expectedDist = 1.5+0.5*std::cos(freq*time);
ASSERT_EQUAL_VEC(Vec3(-0.5*expectedDist, 0, 0), state.getPositions()[0], 0.02);
ASSERT_EQUAL_VEC(Vec3(0.5*expectedDist, 0, 0), state.getPositions()[1], 0.02);
double expectedSpeed = -0.5*freq*std::sin(freq*time);
ASSERT_EQUAL_VEC(Vec3(-0.5*expectedSpeed, 0, 0), state.getVelocities()[0], 0.02);
ASSERT_EQUAL_VEC(Vec3(0.5*expectedSpeed, 0, 0), state.getVelocities()[1], 0.02);
double energy = state.getKineticEnergy()+state.getPotentialEnergy();
ASSERT_EQUAL_TOL(initialEnergy, energy, 0.01);
integrator.step(1);
}
ASSERT_EQUAL_TOL(10.0, context.getState(0).getTime(), 1e-5);
}
void testConstraints() {
const int numParticles = 8;
const int numConstraints = 5;
System system;
VerletIntegrator integrator(0.001);
integrator.setConstraintTolerance(1e-5);
NonbondedForce* forceField = new NonbondedForce();
for (int i = 0; i < numParticles; ++i) {
system.addParticle(i%2 == 0 ? 5.0 : 10.0);
forceField->addParticle((i%2 == 0 ? 0.2 : -0.2), 0.5, 5.0);
}
system.addConstraint(0, 1, 1.0);
system.addConstraint(1, 2, 1.0);
system.addConstraint(2, 3, 1.0);
system.addConstraint(4, 5, 1.0);
system.addConstraint(6, 7, 1.0);
system.addForce(forceField);
Context context(system, integrator, platform);
vector<Vec3> positions(numParticles);
vector<Vec3> velocities(numParticles);
OpenMM_SFMT::SFMT sfmt;
init_gen_rand(0, sfmt);
for (int i = 0; i < numParticles; ++i) {
positions[i] = Vec3(i/2, (i+1)/2, 0);
velocities[i] = Vec3(genrand_real2(sfmt)-0.5, genrand_real2(sfmt)-0.5, genrand_real2(sfmt)-0.5);
}
context.setPositions(positions);
context.setVelocities(velocities);
// Simulate it and see whether the constraints remain satisfied.
double initialEnergy = 0.0;
for (int i = 0; i < 1000; ++i) {
State state = context.getState(State::Positions | State::Energy | State::Velocities | State::Forces);
for (int j = 0; j < numConstraints; ++j) {
int particle1, particle2;
double distance;
system.getConstraintParameters(j, particle1, particle2, distance);
Vec3 p1 = state.getPositions()[particle1];
Vec3 p2 = state.getPositions()[particle2];
double dist = std::sqrt((p1[0]-p2[0])*(p1[0]-p2[0])+(p1[1]-p2[1])*(p1[1]-p2[1])+(p1[2]-p2[2])*(p1[2]-p2[2]));
ASSERT_EQUAL_TOL(distance, dist, 1e-4);
}
double energy = state.getPotentialEnergy()+state.getKineticEnergy();
if (i == 1)
initialEnergy = energy;
else if (i > 1)
ASSERT_EQUAL_TOL(initialEnergy, energy, 0.01);
integrator.step(1);
}
}
void testConstrainedClusters() {
const int numParticles = 7;
System system;
VerletIntegrator integrator(0.001);
integrator.setConstraintTolerance(1e-5);
NonbondedForce* forceField = new NonbondedForce();
for (int i = 0; i < numParticles; ++i) {
system.addParticle(i > 1 ? 1.0 : 10.0);
forceField->addParticle((i%2 == 0 ? 0.2 : -0.2), 0.5, 5.0);
}
system.addConstraint(0, 1, 1.0);
system.addConstraint(0, 2, 1.0);
system.addConstraint(0, 3, 1.0);
system.addConstraint(0, 4, 1.0);
system.addConstraint(1, 5, 1.0);
system.addConstraint(1, 6, 1.0);
system.addConstraint(2, 3, sqrt(2.0));
system.addConstraint(2, 4, sqrt(2.0));
system.addConstraint(3, 4, sqrt(2.0));
system.addConstraint(5, 6, sqrt(2.0));
system.addForce(forceField);
Context context(system, integrator, platform);
vector<Vec3> positions(numParticles);
positions[0] = Vec3(0, 0, 0);
positions[1] = Vec3(1, 0, 0);
positions[2] = Vec3(-1, 0, 0);
positions[3] = Vec3(0, 1, 0);
positions[4] = Vec3(0, 0, 1);
positions[5] = Vec3(2, 0, 0);
positions[6] = Vec3(1, 1, 0);
vector<Vec3> velocities(numParticles);
OpenMM_SFMT::SFMT sfmt;
init_gen_rand(0, sfmt);
for (int i = 0; i < numParticles; ++i)
velocities[i] = Vec3(genrand_real2(sfmt)-0.5, genrand_real2(sfmt)-0.5, genrand_real2(sfmt)-0.5);
context.setPositions(positions);
context.setVelocities(velocities);
// Simulate it and see whether the constraints remain satisfied.
double initialEnergy = 0.0;
for (int i = 0; i < 1000; ++i) {
State state = context.getState(State::Positions | State::Energy | State::Velocities | State::Forces);
for (int j = 0; j < system.getNumConstraints(); ++j) {
int particle1, particle2;
double distance;
system.getConstraintParameters(j, particle1, particle2, distance);
Vec3 p1 = state.getPositions()[particle1];
Vec3 p2 = state.getPositions()[particle2];
double dist = std::sqrt((p1[0]-p2[0])*(p1[0]-p2[0])+(p1[1]-p2[1])*(p1[1]-p2[1])+(p1[2]-p2[2])*(p1[2]-p2[2]));
ASSERT_EQUAL_TOL(distance, dist, 2e-5);
}
double energy = state.getPotentialEnergy()+state.getKineticEnergy();
if (i == 1)
initialEnergy = energy;
else if (i > 1)
ASSERT_EQUAL_TOL(initialEnergy, energy, 0.01);
integrator.step(1);
}
}
void testConstrainedMasslessParticles() {
System system;
system.addParticle(0.0);
system.addParticle(1.0);
system.addConstraint(0, 1, 1.5);
vector<Vec3> positions(2);
positions[0] = Vec3(-1, 0, 0);
positions[1] = Vec3(1, 0, 0);
VerletIntegrator integrator(0.01);
bool failed = false;
try {
// This should throw an exception.
Context context(system, integrator, platform);
}
catch (exception& ex) {
failed = true;
}
ASSERT(failed);
// Now make both particles massless, which should work.
system.setParticleMass(1, 0.0);
Context context(system, integrator, platform);
context.setPositions(positions);
context.setVelocitiesToTemperature(300.0);
integrator.step(1);
State state = context.getState(State::Velocities);
ASSERT_EQUAL(0.0, state.getVelocities()[0][0]);
}
void runPlatformTests();
int main(int argc, char* argv[]) {
try {
initializeTests(argc, argv);
testSingleBond();
testConstraints();
testConstrainedClusters();
testConstrainedMasslessParticles();
runPlatformTests();
}
catch(const exception& e) {
cout << "exception: " << e.what() << endl;
return 1;
}
cout << "Done" << endl;
return 0;
}
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