Merge pull request #1639 from jchodera/update-docs

Update docstrings to specify units and domain for torsions

docs-source/usersguide/theory.rst

@@ -920,7 +920,8 @@ of four particles.  That is, the interaction energy of each bond is given by
 
 where *f*\ (\ *...*\ ) is a user defined mathematical expression.  It may
 depend on an arbitrary set of positions {\ :math:`x_i`\ }, distances {\ :math:`r_i`\ },
-angles {\ :math:`\theta_i`\ }, and dihedral angles {\ :math:`\phi_i`\ }.
+angles {\ :math:`\theta_i`\ }, and dihedral angles {\ :math:`\phi_i`\ }
+guaranteed to be in the range [-π, π]. 
 
 Each distance, angle, or dihedral is defined by specifying a sequence of
 particles chosen from among the particles that make up the bond.  A distance

openmmapi/include/openmm/CustomCompoundBondForce.h

@@ -57,7 +57,7 @@ namespace OpenMM {
  * <li>distance(p1, p2): the distance between particles p1 and p2 (where "p1" and "p2" may be replaced by the names
  * of whichever particles you want to calculate the distance between).</li>
  * <li>angle(p1, p2, p3): the angle formed by the three specified particles.</li>
- * <li>dihedral(p1, p2, p3, p4): the dihedral angle formed by the four specified particles.</li>
+ * <li>dihedral(p1, p2, p3, p4): the dihedral angle formed by the four specified particles, guaranteed to be in the range [-pi,+pi].</li>
  * </ul>
  *
  * The expression also may involve tabulated functions, and may depend on arbitrary

openmmapi/include/openmm/CustomTorsionForce.h

@@ -52,6 +52,7 @@ namespace OpenMM {
  * part of the system definition, while values of global parameters may be modified during a simulation by calling Context::setParameter().
  * Finally, call addTorsion() once for each torsion.  After an torsion has been added, you can modify its parameters by calling setTorsionParameters().
  * This will have no effect on Contexts that already exist unless you call updateParametersInContext().
+ * theta is guaranteed to be in the range [-pi,+pi]
  *
  * As an example, the following code creates a CustomTorsionForce that implements a harmonic potential:
  *