IMP  2.0.1
The Integrative Modeling Platform
IMP::kernel::Constraint Class Referenceabstract

Implement a constraint on the Model. More...

#include <IMP/kernel/Constraint.h>

+ Inheritance diagram for IMP::kernel::Constraint:

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::kernel::ScoreState
 ScoreState (Model *m, std::string name="ScoreState %1%")
 
void after_evaluate (DerivativeAccumulator *accpt)
 Do post evaluation work if needed.
 
void before_evaluate ()
 Force update of the structure.
 
ContainersTemp get_input_containers () const
 
ParticlesTemp get_input_particles () const
 
ContainersTemp get_output_containers () const
 
ParticlesTemp get_output_particles () const
 
- Public Member Functions inherited from IMP::kernel::ModelObject
 ModelObject (Model *m, std::string name)
 
ModelObjectsTemp get_inputs () const
 
ModelObjectsTemps get_interactions () const
 
Modelget_model () const
 
ModelObjectsTemp get_outputs () const
 
- Public Member Functions inherited from IMP::base::Object
virtual void clear_caches ()
 
virtual IMP::base::VersionInfo get_version_info () const =0
 Get information about the module and version of the object.
 
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)
 

Related Functions

(Note that these are not member functions.)

typedef IMP::base::Vector
< IMP::base::WeakPointer
< Constraint > > 
ConstraintsTemp
 

Additional Inherited Members

- Protected Member Functions inherited from IMP::kernel::ScoreState
virtual void do_update_dependencies ()
 

Detailed Description

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.

Note
Constraint invariants will not necessarily hold if involved particles have been called and Model::evaluate() has not been called. For example, if you change a particle's coordinates, a IMP::core::Centroid of a set containing the particle will not be correct until the Model is evaluated.
Implementors
Developers who wish to implement a Constraint should inherit from this class and use the IMP_CONSTRAINT() macro to help define the needed functions. Lamentably, we do not provide an example.

Definition at line 50 of file kernel/Constraint.h.

Friends And Related Function Documentation

Pass a set of objects.

Definition at line 70 of file kernel/Constraint.h.


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