Custom functions are now represented by natural splines

platforms/reference/tests/TestReferenceCustomHbondForce.cpp

@@ -195,7 +195,7 @@ void testCustomFunctions() {
     vector<double> function(2);
     function[0] = 0;
     function[1] = 1;
-    custom->addFunction("foo", function, 0, 10, true);
+    custom->addFunction("foo", function, 0, 10);
     system.addForce(custom);
     Context context(system, integrator, platform);
     vector<Vec3> positions(3);

platforms/reference/tests/TestReferenceCustomNonbondedForce.cpp

@@ -203,7 +203,7 @@ void testPeriodic() {
     ASSERT_EQUAL_TOL(1.9+1+0.9, state.getPotentialEnergy(), TOL);
 }
 
-void testTabulatedFunction(bool interpolating) {
+void testTabulatedFunction() {
     ReferencePlatform platform;
     System system;
     system.addParticle(1.0);
@@ -215,7 +215,7 @@ void testTabulatedFunction(bool interpolating) {
     vector<double> table;
     for (int i = 0; i < 21; i++)
         table.push_back(std::sin(0.25*i));
-    forceField->addFunction("fn", table, 1.0, 6.0, interpolating);
+    forceField->addFunction("fn", table, 1.0, 6.0);
     system.addForce(forceField);
     Context context(system, integrator, platform);
     vector<Vec3> positions(2);
@@ -233,6 +233,14 @@ void testTabulatedFunction(bool interpolating) {
         ASSERT_EQUAL_VEC(Vec3(force, 0, 0), forces[1], 0.1);
         ASSERT_EQUAL_TOL(energy, state.getPotentialEnergy(), 0.02);
     }
+    for (int i = 1; i < 20; i++) {
+        double x = 0.25*i+1.0;
+        positions[1] = Vec3(x, 0, 0);
+        context.setPositions(positions);
+        State state = context.getState(State::Energy);
+        double energy = (x < 1.0 || x > 6.0 ? 0.0 : std::sin(x-1.0))+1.0;
+        ASSERT_EQUAL_TOL(energy, state.getPotentialEnergy(), 1e-4);
+    }
 }
 
 void testCoulombLennardJones() {
@@ -317,8 +325,7 @@ int main() {
         testExclusions();
         testCutoff();
         testPeriodic();
-        testTabulatedFunction(true);
-        testTabulatedFunction(false);
+        testTabulatedFunction();
         testCoulombLennardJones();
     }
     catch(const exception& e) {

serialization/src/CustomGBForceProxy.cpp

@@ -91,9 +91,8 @@ void CustomGBForceProxy::serialize(const void* object, SerializationNode& node)
         string name;
         vector<double> values;
         double min, max;
-        bool interpolating;
-        force.getFunctionParameters(i, name, values, min, max, interpolating);
-        SerializationNode& node = functions.createChildNode("Function").setStringProperty("name", name).setDoubleProperty("min", min).setDoubleProperty("max", max).setIntProperty("interpolating", interpolating);
+        force.getFunctionParameters(i, name, values, min, max);
+        SerializationNode& node = functions.createChildNode("Function").setStringProperty("name", name).setDoubleProperty("min", min).setDoubleProperty("max", max);
         SerializationNode& valuesNode = node.createChildNode("Values");
         for (int j = 0; j < (int) values.size(); j++)
             valuesNode.createChildNode("Value").setDoubleProperty("v", values[j]);
@@ -152,7 +151,7 @@ void* CustomGBForceProxy::deserialize(const SerializationNode& node) const {
             vector<double> values;
             for (int j = 0; j < (int) valuesNode.getChildren().size(); j++)
                 values.push_back(valuesNode.getChildren()[j].getDoubleProperty("v"));
-            force->addFunction(function.getStringProperty("name"), values, function.getDoubleProperty("min"), function.getDoubleProperty("max"), (bool) function.getIntProperty("interpolating"));
+            force->addFunction(function.getStringProperty("name"), values, function.getDoubleProperty("min"), function.getDoubleProperty("max"));
         }
         return force;
     }

serialization/src/CustomHbondForceProxy.cpp

@@ -96,9 +96,8 @@ void CustomHbondForceProxy::serialize(const void* object, SerializationNode& nod
         string name;
         vector<double> values;
         double min, max;
-        bool interpolating;
-        force.getFunctionParameters(i, name, values, min, max, interpolating);
-        SerializationNode& node = functions.createChildNode("Function").setStringProperty("name", name).setDoubleProperty("min", min).setDoubleProperty("max", max).setIntProperty("interpolating", interpolating);
+        force.getFunctionParameters(i, name, values, min, max);
+        SerializationNode& node = functions.createChildNode("Function").setStringProperty("name", name).setDoubleProperty("min", min).setDoubleProperty("max", max);
         SerializationNode& valuesNode = node.createChildNode("Values");
         for (int j = 0; j < (int) values.size(); j++)
             valuesNode.createChildNode("Value").setDoubleProperty("v", values[j]);
@@ -164,7 +163,7 @@ void* CustomHbondForceProxy::deserialize(const SerializationNode& node) const {
             vector<double> values;
             for (int j = 0; j < (int) valuesNode.getChildren().size(); j++)
                 values.push_back(valuesNode.getChildren()[j].getDoubleProperty("v"));
-            force->addFunction(function.getStringProperty("name"), values, function.getDoubleProperty("min"), function.getDoubleProperty("max"), (bool) function.getIntProperty("interpolating"));
+            force->addFunction(function.getStringProperty("name"), values, function.getDoubleProperty("min"), function.getDoubleProperty("max"));
         }
         return force;
     }

serialization/src/CustomNonbondedForceProxy.cpp

@@ -78,9 +78,8 @@ void CustomNonbondedForceProxy::serialize(const void* object, SerializationNode&
         string name;
         vector<double> values;
         double min, max;
-        bool interpolating;
-        force.getFunctionParameters(i, name, values, min, max, interpolating);
-        SerializationNode& node = functions.createChildNode("Function").setStringProperty("name", name).setDoubleProperty("min", min).setDoubleProperty("max", max).setIntProperty("interpolating", interpolating);
+        force.getFunctionParameters(i, name, values, min, max);
+        SerializationNode& node = functions.createChildNode("Function").setStringProperty("name", name).setDoubleProperty("min", min).setDoubleProperty("max", max);
         SerializationNode& valuesNode = node.createChildNode("Values");
         for (int j = 0; j < (int) values.size(); j++)
             valuesNode.createChildNode("Value").setDoubleProperty("v", values[j]);
@@ -129,7 +128,7 @@ void* CustomNonbondedForceProxy::deserialize(const SerializationNode& node) cons
             vector<double> values;
             for (int j = 0; j < (int) valuesNode.getChildren().size(); j++)
                 values.push_back(valuesNode.getChildren()[j].getDoubleProperty("v"));
-            force->addFunction(function.getStringProperty("name"), values, function.getDoubleProperty("min"), function.getDoubleProperty("max"), (bool) function.getIntProperty("interpolating"));
+            force->addFunction(function.getStringProperty("name"), values, function.getDoubleProperty("min"), function.getDoubleProperty("max"));
         }
         return force;
     }

serialization/tests/TestSerializeCustomGBForce.cpp

@@ -63,7 +63,7 @@ void testSerialization() {
     vector<double> values(10);
     for (int i = 0; i < 10; i++)
         values[i] = sin((double) i);
-    force.addFunction("f", values, 0.5, 1.5, true);
+    force.addFunction("f", values, 0.5, 1.5);
 
     // Serialize and then deserialize it.
 
@@ -125,13 +125,11 @@ void testSerialization() {
         string name1, name2;
         double min1, min2, max1, max2;
         vector<double> val1, val2;
-        bool interp1, interp2;
-        force.getFunctionParameters(i, name1, val1, min1, max1, interp1);
-        force2.getFunctionParameters(i, name2, val2, min2, max2, interp2);
+        force.getFunctionParameters(i, name1, val1, min1, max1);
+        force2.getFunctionParameters(i, name2, val2, min2, max2);
         ASSERT_EQUAL(name1, name2);
         ASSERT_EQUAL(min1, min2);
         ASSERT_EQUAL(max1, max2);
-        ASSERT_EQUAL(interp1, interp2);
         ASSERT_EQUAL(val1.size(), val2.size());
         for (int j = 0; j < val1.size(); j++)
             ASSERT_EQUAL(val1[j], val2[j]);

serialization/tests/TestSerializeCustomHbondForce.cpp

@@ -66,7 +66,7 @@ void testSerialization() {
     vector<double> values(10);
     for (int i = 0; i < 10; i++)
         values[i] = sin((double) i);
-    force.addFunction("f", values, 0.5, 1.5, true);
+    force.addFunction("f", values, 0.5, 1.5);
 
     // Serialize and then deserialize it.
 
@@ -130,13 +130,11 @@ void testSerialization() {
         string name1, name2;
         double min1, min2, max1, max2;
         vector<double> val1, val2;
-        bool interp1, interp2;
-        force.getFunctionParameters(i, name1, val1, min1, max1, interp1);
-        force2.getFunctionParameters(i, name2, val2, min2, max2, interp2);
+        force.getFunctionParameters(i, name1, val1, min1, max1);
+        force2.getFunctionParameters(i, name2, val2, min2, max2);
         ASSERT_EQUAL(name1, name2);
         ASSERT_EQUAL(min1, min2);
         ASSERT_EQUAL(max1, max2);
-        ASSERT_EQUAL(interp1, interp2);
         ASSERT_EQUAL(val1.size(), val2.size());
         for (int j = 0; j < val1.size(); j++)
             ASSERT_EQUAL(val1[j], val2[j]);

serialization/tests/TestSerializeCustomNonbondedForce.cpp

@@ -59,7 +59,7 @@ void testSerialization() {
     vector<double> values(10);
     for (int i = 0; i < 10; i++)
         values[i] = sin((double) i);
-    force.addFunction("f", values, 0.5, 1.5, true);
+    force.addFunction("f", values, 0.5, 1.5);
 
     // Serialize and then deserialize it.
 
@@ -103,13 +103,11 @@ void testSerialization() {
         string name1, name2;
         double min1, min2, max1, max2;
         vector<double> val1, val2;
-        bool interp1, interp2;
-        force.getFunctionParameters(i, name1, val1, min1, max1, interp1);
-        force2.getFunctionParameters(i, name2, val2, min2, max2, interp2);
+        force.getFunctionParameters(i, name1, val1, min1, max1);
+        force2.getFunctionParameters(i, name2, val2, min2, max2);
         ASSERT_EQUAL(name1, name2);
         ASSERT_EQUAL(min1, min2);
         ASSERT_EQUAL(max1, max2);
-        ASSERT_EQUAL(interp1, interp2);
         ASSERT_EQUAL(val1.size(), val2.size());
         for (int j = 0; j < val1.size(); j++)
             ASSERT_EQUAL(val1[j], val2[j]);