IMP Reference Guide  develop.2de7fdb984,2019/11/19 The Integrative Modeling Platform
IMP::Restraint Class Reference

A restraint is a term in an IMP ScoringFunction. More...

#include "IMP/Restraint.h"

Inherits IMP::ModelObject.

## Detailed Description

A restraint is a term in an IMP ScoringFunction.

To implement a new restraint, just implement the two methods:

Note
When logging is VERBOSE, restraints should print enough information in evaluate to reproduce the the entire flow of data in evaluate. When logging is TERSE the restraint should print out only a constant number of lines per evaluate call.
Physical restraints should use the units of kcal/mol for restraint values and kcal/mol/A for derivatives.

When implementing an expensive restraint it makes sense to support early abort of evaluation if the user is only interested in good scores or scores below a threshold. To do this, look at the fields of the ScoreAccumulator object such as

See IMP::example::ExampleRestraint for an example.

Definition at line 54 of file Restraint.h.

## Public Member Functions

Restraint (Model *m, std::string name)

Perform the actual restraint scoring. More...

Restraintcreate_current_decomposition () const
Decompose this restraint into constituent terms for the current conf. More...

Restraintcreate_decomposition () const
Decompose this restraint into constituent terms. More...

virtual ScoringFunctioncreate_scoring_function (double weight=1.0, double max=NO_MAX) const
Create a scoring function with only this restraint. More...

virtual RestraintInfoget_dynamic_info () const

virtual double get_last_score () const

double get_score () const

virtual RestraintInfoget_static_info () const

bool get_was_good () const

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

## Protected Member Functions

virtual void do_add_score_and_derivatives (ScoreAccumulator sa) const
A restraint should override this to compute the score and derivatives. More...

virtual Restraints do_create_current_decomposition () const

virtual Restraints do_create_decomposition () const

ModelObjectsTemp do_get_outputs () const

Protected Member Functions inherited from IMP::ModelObject
virtual ModelObjectsTemp do_get_inputs () const =0

virtual ModelObjectsTemps do_get_interactions () const

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 ()

## Weights

Each restraint's contribution to the model score is weighted. The total weight for the restraint is the some over all the paths containing it. That is, if a restraint is in a RestraintSet with weight .5 and another with weight 2, and the restraint itself has weight 3, then the total weight of the restraint is $$.5 \cdot 3 + 2 \cdot 3 = 7.5$$.

void set_weight (Float weight)

Float get_weight () const

## Filtering

We are typically only interested in "good" conformations of the model. These are described by specifying maximum scores per restraint (or RestraintSet). Samplers, optimizers etc are free to ignore configurations they encounter which go outside these bounds.

Note
The maximum score is for the unweighted restraint. That is, the restraint evaluation is bad if the value is greater than the maximum score divided by the weight.
double get_maximum_score () const

void set_maximum_score (double s)

## Constructor & Destructor Documentation

 IMP::Restraint::Restraint ( Model * m, std::string name )

Create a restraint and register it with the model. The restraint is not added to the implicit scoring function in the Model.

## Member Function Documentation

 void IMP::Restraint::add_score_and_derivatives ( ScoreAccumulator sa ) const

Perform the actual restraint scoring.

The restraints should assume that all appropriate ScoreState objects have been updated and so that the input particles and containers are up to date. The returned score should be the unweighted score.

 Restraint* IMP::Restraint::create_current_decomposition ( ) const

Decompose this restraint into constituent terms for the current conf.

Returns
a decomposition that is value for the current conformation, but will not necessarily be valid if any of the particles are changed. This is the same as create_decomposition() for non-conditional restraints.

The restraints returned have had set_model() called and so can be evaluated.

 Restraint* IMP::Restraint::create_decomposition ( ) const

Decompose this restraint into constituent terms.

Given the set of input particles, decompose the restraint into parts that are as simple as possible. For many restraints, the simplest part is simply the restraint itself.

If a restraint can be decomposed, it should return a RestraintSet so that the maximum score and weight can be passed properly.

The restraints returned have had set_model() called and so can be evaluated.

 virtual ScoringFunction* IMP::Restraint::create_scoring_function ( double weight = 1.0, double max = NO_MAX ) const
virtual

Create a scoring function with only this restraint.

Note
This method cannot be implemented in Python due to memory management issues (and the question of why you would ever want to).
 virtual void IMP::Restraint::do_add_score_and_derivatives ( ScoreAccumulator sa ) const
protectedvirtual

A restraint should override this to compute the score and derivatives.

 virtual Restraints IMP::Restraint::do_create_current_decomposition ( ) const
protectedvirtual

A Restraint should override this if it wants to decompose itself for display and other purposes. The returned restraints will be made into a RestraintSet if needed, with suitable weight and maximum score.

The returned restraints should be only the non-zero terms and should have their last scores set appropriately.

Definition at line 235 of file Restraint.h.

 virtual Restraints IMP::Restraint::do_create_decomposition ( ) const
protectedvirtual

A Restraint should override this if it wants to decompose itself for domino and other purposes. The returned restraints will be made into a RestraintSet if needed, with suitable weight and maximum score.

Reimplemented in IMP::core::ExcludedVolumeRestraint.

Definition at line 225 of file Restraint.h.

 ModelObjectsTemp IMP::Restraint::do_get_outputs ( ) const
protectedvirtual

No outputs.

Implements IMP::ModelObject.

Definition at line 242 of file Restraint.h.

 virtual RestraintInfo* IMP::Restraint::get_dynamic_info ( ) const
virtual
Returns
a set of key:value pairs that contain dynamic information about this restraint (i.e. information that changes during a sampling run, such as scores or cross correlations). If no such information is available, a null pointer is returned. This information is used when writing restraints to files, e.g. by the IMP.rmf module.

Reimplemented in IMP::isd::GaussianEMRestraint, and IMP::em2d::PCAFitRestraint.

Definition at line 129 of file Restraint.h.

 virtual double IMP::Restraint::get_last_score ( ) const
virtual

Return the (unweighted) score for this restraint last time it was evaluated.

Note
If some sort of special evaluation (eg Model::evaluate_if_good()) was the last call, the score, if larger than the max, is not accurate.

Reimplemented in IMP::RestraintSet.

Definition at line 212 of file Restraint.h.

 double IMP::Restraint::get_score ( ) const

Compute and return the current score for the restraint.

 virtual RestraintInfo* IMP::Restraint::get_static_info ( ) const
virtual
Returns
a set of key:value pairs that contain static information about this restraint (i.e. information that doesn't change during a sampling run, such as the type of restraint or filename from which information is read). Usually this includes a "type" key with the fully qualified classname (e.g. IMP.mymodule.MyRestraint). If no such information is available, a null pointer is returned. This information is used when writing restraints to files, e.g. by the IMP.rmf module.

Reimplemented in IMP::isd::GaussianEMRestraint, and IMP::em2d::PCAFitRestraint.

Definition at line 117 of file Restraint.h.

 bool IMP::Restraint::get_was_good ( ) const

Return whether this restraint violated its maximum last time it was evaluated.

Definition at line 216 of file Restraint.h.

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