Implement a constraint on the Model.
The solution model can be restricted two ways, either by penalizing "bad" conformations (a restraint) or by forcing some set of attributes to a function of other attributes (a constraint). For example, rigid bodies consisting of a number of particles could be implemented either way.
In IMP, constraints are implemented as a type of ScoreState. Before evaluation, the constraint updates the attributes of some of the particles to ensure that the constraint is satisfied. Since this update creates implicit relationships between the particles, after the derivatives are computed, the constraint can move them around to make sure the derivatives of the optimizer parameters are correct.
In general, constraints are associated with Decorator objects and created invisibly when needed.
|Constraint (std::string name="Constraint %1%")|