gtsam::LinearContainerFactor Class Reference

Detailed Description

Dummy version of a generic linear factor to be injected into a nonlinear factor graph.

This factor does have the ability to perform relinearization under small-angle and linearity assumptions if a linearization point is added.

Inheritance diagram for gtsam::LinearContainerFactor:

Public Member Functions
	LinearContainerFactor (const JacobianFactor &factor, const Values &linearizationPoint=Values())
	Primary constructor: store a linear factor with optional linearization point.
	LinearContainerFactor (const HessianFactor &factor, const Values &linearizationPoint=Values())
	Primary constructor: store a linear factor with optional linearization point.
	LinearContainerFactor (const GaussianFactor::shared_ptr &factor, const Values &linearizationPoint=Values())
	Constructor from shared_ptr.
const GaussianFactor::shared_ptr &	factor () const
void	print (const std::string &s="", const KeyFormatter &keyFormatter=gtsam::DefaultKeyFormatter) const
	print
bool	equals (const NonlinearFactor &f, double tol=1e-9) const
	Check if two factors are equal.
double	error (const Values &c) const
	Calculate the nonlinear error for the factor, where the error is computed by passing the delta between linearization point and c, where delta = linearizationPoint_.localCoordinates(c), into the error function of the stored linear factor. More...
size_t	dim () const
	get the dimension of the factor: rows of linear factor
const boost::optional< Values > &	linearizationPoint () const
	Extract the linearization point used in recalculating error.
GaussianFactor::shared_ptr	linearize (const Values &c) const
	Linearize to a GaussianFactor, with method depending on the presence of a linearizationPoint. More...
GaussianFactor::shared_ptr	negateToGaussian () const
	Creates an anti-factor directly.
NonlinearFactor::shared_ptr	negateToNonlinear () const
	Creates the equivalent anti-factor as another LinearContainerFactor.
NonlinearFactor::shared_ptr	clone () const
	Creates a shared_ptr clone of the factor - needs to be specialized to allow for subclasses. More...
bool	hasLinearizationPoint () const
bool	isJacobian () const
	Simple checks whether this is a Jacobian or Hessian factor.
bool	isHessian () const
boost::shared_ptr< JacobianFactor >	toJacobian () const
	Casts to JacobianFactor.
boost::shared_ptr< HessianFactor >	toHessian () const
	Casts to HessianFactor.
Public Member Functions inherited from gtsam::NonlinearFactor
	NonlinearFactor ()
	Default constructor for I/O only.
template<typename CONTAINER >
	NonlinearFactor (const CONTAINER &keys)
	Constructor from a collection of the keys involved in this factor.
virtual	~NonlinearFactor ()
	Destructor.
virtual bool	active (const Values &) const
	Checks whether a factor should be used based on a set of values. More...
shared_ptr	rekey (const std::map< Key, Key > &rekey_mapping) const
	Creates a shared_ptr clone of the factor with different keys using a map from old->new keys.
shared_ptr	rekey (const KeyVector &new_keys) const
	Clones a factor and fully replaces its keys. More...
Public Member Functions inherited from gtsam::Factor
Key	front () const
	First key.
Key	back () const
	Last key.
const_iterator	find (Key key) const
	find
const KeyVector &	keys () const
	Access the factor's involved variable keys.
const_iterator	begin () const
	Iterator at beginning of involved variable keys.
const_iterator	end () const
	Iterator at end of involved variable keys.
size_t	size () const
void	print (const std::string &s="Factor", const KeyFormatter &formatter=DefaultKeyFormatter) const
	print
void	printKeys (const std::string &s="Factor", const KeyFormatter &formatter=DefaultKeyFormatter) const
	print only keys
KeyVector &	keys ()
iterator	begin ()
	Iterator at beginning of involved variable keys.
iterator	end ()
	Iterator at end of involved variable keys.

Static Public Member Functions
static NonlinearFactorGraph	ConvertLinearGraph (const GaussianFactorGraph &linear_graph, const Values &linearizationPoint=Values())
	Utility function for converting linear graphs to nonlinear graphs consisting of LinearContainerFactors.

Public Types
typedef boost::shared_ptr< This >	shared_ptr
Public Types inherited from gtsam::NonlinearFactor
typedef boost::shared_ptr< This >	shared_ptr
Public Types inherited from gtsam::Factor
typedef KeyVector::iterator	iterator
	Iterator over keys.
typedef KeyVector::const_iterator	const_iterator
	Const iterator over keys.

Protected Types
typedef NonlinearFactor	Base
typedef LinearContainerFactor	This
Protected Types inherited from gtsam::NonlinearFactor
typedef Factor	Base
typedef NonlinearFactor	This

Protected Member Functions
	LinearContainerFactor ()
	Default constructor - necessary for serialization.
	LinearContainerFactor (const GaussianFactor::shared_ptr &factor, const boost::optional< Values > &linearizationPoint)
	direct copy constructor
void	initializeLinearizationPoint (const Values &linearizationPoint)
Protected Member Functions inherited from gtsam::Factor
	Factor ()
	Default constructor for I/O.
template<typename CONTAINER >
	Factor (const CONTAINER &keys)
	Construct factor from container of keys. More...
template<typename ITERATOR >
	Factor (ITERATOR first, ITERATOR last)
	Construct factor from iterator keys. More...
bool	equals (const This &other, double tol=1e-9) const
	check equality

Protected Attributes
GaussianFactor::shared_ptr	factor_
boost::optional< Values >	linearizationPoint_
Protected Attributes inherited from gtsam::Factor
KeyVector	keys_
	The keys involved in this factor.

Friends
class	boost::serialization::access
	Serialization function.

Additional Inherited Members
Static Protected Member Functions inherited from gtsam::Factor
template<typename CONTAINER >
static Factor	FromKeys (const CONTAINER &keys)
	Construct factor from container of keys. More...
template<typename ITERATOR >
static Factor	FromIterators (ITERATOR first, ITERATOR last)
	Construct factor from iterator keys. More...

Member Function Documentation

clone()

NonlinearFactor::shared_ptr gtsam::LinearContainerFactor::clone ( ) const

inlinevirtual

Creates a shared_ptr clone of the factor - needs to be specialized to allow for subclasses.

Clones the underlying linear factor

Reimplemented from gtsam::NonlinearFactor.

error()

double gtsam::LinearContainerFactor::error ( const Values &  c ) const

virtual

Calculate the nonlinear error for the factor, where the error is computed by passing the delta between linearization point and c, where delta = linearizationPoint_.localCoordinates(c), into the error function of the stored linear factor.

Returns

nonlinear error if linearizationPoint present, zero otherwise

Implements gtsam::NonlinearFactor.

linearize()

GaussianFactor::shared_ptr gtsam::LinearContainerFactor::linearize ( const Values &  c ) const

virtual

Linearize to a GaussianFactor, with method depending on the presence of a linearizationPoint.

• With no linearization point, returns a cloned version of the stored linear factor.
• With a linearization point provided, returns a relinearized version of the linearized factor.

The relinearization approach used computes a linear delta between the original linearization point and the new values c, where delta = linearizationPoint_.localCoordinates(c), and substitutes this change into the system. This substitution is only really valid for linear variable manifolds, and for any variables based on a non-commutative manifold (such as Pose2, Pose3), the relinearized version will be effective for only small angles.

TODO: better approximation of relinearization TODO: switchable modes for approximation technique

Implements gtsam::NonlinearFactor.

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

• /Users/dellaert/git/gtsam/gtsam/nonlinear/LinearContainerFactor.h
• /Users/dellaert/git/gtsam/gtsam/nonlinear/LinearContainerFactor.cpp