GTSAM  4.0.2
C++ library for smoothing and mapping (SAM)
Public Types | Public Member Functions | Protected Attributes | List of all members
gtsam::noiseModel::mEstimator::Base Class Referenceabstract

#include <LossFunctions.h>

Inheritance diagram for gtsam::noiseModel::mEstimator::Base:
Inheritance graph
[legend]

Public Types

enum  ReweightScheme { Scalar, Block }
 
typedef std::shared_ptr< Baseshared_ptr
 

Public Member Functions

 Base (const ReweightScheme reweight=Block)
 
ReweightScheme reweightScheme () const
 Returns the reweight scheme, as explained in ReweightScheme.
 
virtual double loss (double distance) const
 
virtual double weight (double distance) const =0
 
virtual void print (const std::string &s) const =0
 
virtual bool equals (const Base &expected, double tol=1e-8) const =0
 
double sqrtWeight (double distance) const
 
Vector weight (const Vector &error) const
 
Vector sqrtWeight (const Vector &error) const
 
void reweight (Vector &error) const
 
void reweight (std::vector< Matrix > &A, Vector &error) const
 
void reweight (Matrix &A, Vector &error) const
 
void reweight (Matrix &A1, Matrix &A2, Vector &error) const
 
void reweight (Matrix &A1, Matrix &A2, Matrix &A3, Vector &error) const
 

Protected Attributes

ReweightScheme reweight_
 Strategy for reweighting. More...
 

Detailed Description

Pure virtual class for all robust error function classes.

It provides the machinery for block vs scalar reweighting strategies, in addition to defining the interface of derived classes.

Member Enumeration Documentation

◆ ReweightScheme

the rows can be weighted independently according to the error or uniformly with the norm of the right hand side

Member Function Documentation

◆ loss()

virtual double gtsam::noiseModel::mEstimator::Base::loss ( double  distance) const
inlinevirtual

This method is responsible for returning the total penalty for a given amount of error. For example, this method is responsible for implementing the quadratic function for an L2 penalty, the absolute value function for an L1 penalty, etc.

TODO(mikebosse): When the loss function has as input the norm of the error vector, then it prevents implementations of asymmeric loss functions. It would be better for this function to accept the vector and internally call the norm if necessary.

This returns (x) in mEstimator

Reimplemented in gtsam::noiseModel::mEstimator::L2WithDeadZone, gtsam::noiseModel::mEstimator::DCS, gtsam::noiseModel::mEstimator::GemanMcClure, gtsam::noiseModel::mEstimator::Welsch, gtsam::noiseModel::mEstimator::Tukey, gtsam::noiseModel::mEstimator::Cauchy, gtsam::noiseModel::mEstimator::Huber, gtsam::noiseModel::mEstimator::Fair, and gtsam::noiseModel::mEstimator::Null.

◆ reweight()

void gtsam::noiseModel::mEstimator::Base::reweight ( Vector &  error) const

reweight block matrices and a vector according to their weight implementation

◆ sqrtWeight()

Vector gtsam::noiseModel::mEstimator::Base::sqrtWeight ( const Vector &  error) const

square root version of the weight function

◆ weight() [1/2]

virtual double gtsam::noiseModel::mEstimator::Base::weight ( double  distance) const
pure virtual

This method is responsible for returning the weight function for a given amount of error. The weight function is related to the analytic derivative of the loss function. See https://members.loria.fr/MOBerger/Enseignement/Master2/Documents/ZhangIVC-97-01.pdf for details. This method is required when optimizing cost functions with robust penalties using iteratively re-weighted least squares.

This returns w(x) in mEstimator

Implemented in gtsam::noiseModel::mEstimator::L2WithDeadZone, gtsam::noiseModel::mEstimator::DCS, gtsam::noiseModel::mEstimator::GemanMcClure, gtsam::noiseModel::mEstimator::Welsch, gtsam::noiseModel::mEstimator::Tukey, gtsam::noiseModel::mEstimator::Cauchy, gtsam::noiseModel::mEstimator::Huber, gtsam::noiseModel::mEstimator::Fair, and gtsam::noiseModel::mEstimator::Null.

◆ weight() [2/2]

Vector gtsam::noiseModel::mEstimator::Base::weight ( const Vector &  error) const

produce a weight vector according to an error vector and the implemented robust function

Member Data Documentation

◆ reweight_

ReweightScheme gtsam::noiseModel::mEstimator::Base::reweight_
protected

Strategy for reweighting.

See also
ReweightScheme

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