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IMP Reference Guide  2.7.0
The Integrative Modeling Platform
IMP::Constraint Class Referenceabstract

Implement a constraint on the Model. More...

#include <IMP/Constraint.h>

+ Inheritance diagram for IMP::Constraint:

Detailed Description

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.

  • As a restraint: the particles in the rigid body are each moved independently by the optimizer. The scoring function has a term for how far each particle diverges from its rigid position.
  • As a constraint: the optimizer only changes the position of the rigid body itself and the position of the particles in the body are computed from the position of the rigid body.

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 invariants will not necessarily hold if involved particles have been modified directly (not through e.g., an Optimizer), until Model::update() or Model::evaluate() have been called. For example, if you change a particle's coordinates, a IMP::core::Centroid of a set of particles that contains the particle, will not be the correct centroid until the Model is updated.

Definition at line 49 of file Constraint.h.

Public Member Functions

 Constraint (Model *m, std::string name="Constraint %1%")
virtual void do_after_evaluate (DerivativeAccumulator *da)
virtual void do_before_evaluate ()
virtual void do_update_attributes ()=0
virtual void do_update_derivatives (DerivativeAccumulator *da)=0
- Public Member Functions inherited from IMP::ScoreState
 ScoreState (Model *m, std::string name)
void after_evaluate (DerivativeAccumulator *accpt)
 Do post evaluation work if needed. More...
void before_evaluate ()
 Force update of the structure. More...
- Public Member Functions inherited from IMP::ModelObject
 ModelObject (Model *m, std::string name)
bool get_has_dependencies () const
 Return whether this object has dependencies computed. More...
bool get_has_required_score_states () const
 Return whether score states are computed. More...
ModelObjectsTemp get_inputs () const
ModelObjectsTemps get_interactions () const
 Get the interacting sets induced by this ModelObject. More...
Modelget_model () const
ModelObjectsTemp get_outputs () const
const ScoreStatesTempget_required_score_states () const
 Get the score states that are ancestors of this in the dependency graph. More...
void set_has_dependencies (bool tf)
 Either invalidate the dependencies or ensure they are correct. More...
void set_has_required_score_states (bool tf)
 Compute the required score states. More...
- Public Member Functions inherited from IMP::Object
virtual void clear_caches ()
CheckLevel get_check_level () const
LogLevel get_log_level () const
virtual VersionInfo get_version_info () const
 Get information about the module and version of the object. More...
void set_check_level (CheckLevel l)
void set_log_level (LogLevel l)
 Set the logging level used in this object. More...
void set_was_used (bool tf) const
void show (std::ostream &out=std::cout) const
const std::string & get_name () const
void set_name (std::string name)
virtual std::string get_type_name () const

Additional Inherited Members

- Protected Member Functions inherited from IMP::ModelObject
virtual ModelObjectsTemp do_get_inputs () const =0
virtual ModelObjectsTemps do_get_interactions () const
virtual ModelObjectsTemp do_get_outputs () const =0
virtual void handle_set_has_required_score_states (bool)
- Protected Member Functions inherited from IMP::Object
 Object (std::string name)
 Construct an object with the given name. More...
virtual void do_destroy ()

The documentation for this class was generated from the following file: