gtsam 4.1.1
gtsam
gtsam::ExpressionFactor< T > Class Template Reference

Detailed Description

template<typename T>
class gtsam::ExpressionFactor< T >

Factor that supports arbitrary expressions via AD.

Arbitrary instances of this template can be directly inserted into a factor graph for optimization. However, to enable the correct (de)serialization of such instances, the user should declare derived classes from this template, implementing expresion(), serialize(), clone(), print(), and defining the corresponding struct traits<NewFactor> : public Testable<NewFactor> {}.

Template Parameters
TType for measurements.
+ Inheritance diagram for gtsam::ExpressionFactor< T >:

Public Member Functions

 ExpressionFactor (const SharedNoiseModel &noiseModel, const T &measurement, const Expression< T > &expression)
 Constructor: creates a factor from a measurement and measurement function. More...
 
 ~ExpressionFactor () override
 Destructor.
 
const T & measured () const
 return the measurement
 
void print (const std::string &s="", const KeyFormatter &keyFormatter=DefaultKeyFormatter) const override
 print relies on Testable traits being defined for T More...
 
bool equals (const NonlinearFactor &f, double tol) const override
 equals relies on Testable traits being defined for T More...
 
Vector unwhitenedError (const Values &x, boost::optional< std::vector< Matrix > & > H=boost::none) const override
 Error function without the NoiseModel, \( z-h(x) -> Local(h(x),z) \). More...
 
boost::shared_ptr< GaussianFactorlinearize (const Values &x) const override
 linearize to a GaussianFactor More...
 
gtsam::NonlinearFactor::shared_ptr clone () const override
 
- Public Member Functions inherited from gtsam::NoiseModelFactor
 NoiseModelFactor ()
 Default constructor for I/O only.
 
 ~NoiseModelFactor () override
 Destructor.
 
template<typename CONTAINER >
 NoiseModelFactor (const SharedNoiseModel &noiseModel, const CONTAINER &keys)
 Constructor.
 
void print (const std::string &s="", const KeyFormatter &keyFormatter=DefaultKeyFormatter) const override
 Print. More...
 
bool equals (const NonlinearFactor &f, double tol=1e-9) const override
 Check if two factors are equal. More...
 
size_t dim () const override
 get the dimension of the factor (number of rows on linearization) More...
 
const SharedNoiseModelnoiseModel () const
 access to the noise model
 
virtual Vector unwhitenedError (const Values &x, boost::optional< std::vector< Matrix > & > H=boost::none) const =0
 Error function without the NoiseModel, \( z-h(x) \). More...
 
Vector whitenedError (const Values &c) const
 Vector of errors, whitened This is the raw error, i.e., i.e. More...
 
Vector unweightedWhitenedError (const Values &c) const
 Vector of errors, whitened, but unweighted by any loss function.
 
double weight (const Values &c) const
 Compute the effective weight of the factor from the noise model.
 
double error (const Values &c) const override
 Calculate the error of the factor. More...
 
boost::shared_ptr< GaussianFactorlinearize (const Values &x) const override
 Linearize a non-linearFactorN to get a GaussianFactor, \( Ax-b \approx h(x+\delta x)-z = h(x) + A \delta x - z \) Hence \( b = z - h(x) = - \mathtt{error\_vector}(x) \). More...
 
shared_ptr cloneWithNewNoiseModel (const SharedNoiseModel newNoise) const
 Creates a shared_ptr clone of the factor with a new noise model.
 
- 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...
 
virtual 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. More...
 
virtual shared_ptr rekey (const KeyVector &new_keys) const
 Clones a factor and fully replaces its keys. More...
 
virtual bool sendable () const
 Should the factor be evaluated in the same thread as the caller This is to enable factors that has shared states (like the Python GIL lock) More...
 
- Public Member Functions inherited from gtsam::Factor
virtual ~Factor ()=default
 Default destructor.
 
KeyVectorkeys ()
 
iterator begin ()
 Iterator at beginning of involved variable keys.
 
iterator end ()
 Iterator at end of involved variable keys.
 
virtual void printKeys (const std::string &s="Factor", const KeyFormatter &formatter=DefaultKeyFormatter) const
 print only keys More...
 
Key front () const
 First key.
 
Key back () const
 Last key.
 
const_iterator find (Key key) const
 find
 
const KeyVectorkeys () 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
 

Public Types

typedef boost::shared_ptr< ExpressionFactor< T > > shared_ptr
 
- Public Types inherited from gtsam::NoiseModelFactor
typedef boost::shared_ptr< Thisshared_ptr
 Noise model.
 
- Public Types inherited from gtsam::NonlinearFactor
typedef boost::shared_ptr< Thisshared_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 ExpressionFactor< T > This
 
- Protected Types inherited from gtsam::NoiseModelFactor
typedef NonlinearFactor Base
 
typedef NoiseModelFactor This
 
- Protected Types inherited from gtsam::NonlinearFactor
typedef Factor Base
 
typedef NonlinearFactor This
 

Protected Member Functions

 ExpressionFactor (const SharedNoiseModel &noiseModel, const T &measurement)
 Default constructor, for serialization. More...
 
void initialize (const Expression< T > &expression)
 Initialize with constructor arguments.
 
virtual Expression< T > expression () const
 Recreate expression from keys_ and measured_, used in load below. More...
 
- Protected Member Functions inherited from gtsam::NoiseModelFactor
 NoiseModelFactor (const SharedNoiseModel &noiseModel)
 Constructor - only for subclasses, as this does not set keys.
 
- 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

measured_
 the measurement to be compared with the expression
 
Expression< T > expression_
 the expression that is AD enabled
 
FastVector< int > dims_
 dimensions of the Jacobian matrices
 
- Protected Attributes inherited from gtsam::NoiseModelFactor
SharedNoiseModel noiseModel_
 
- Protected Attributes inherited from gtsam::Factor
KeyVector keys_
 The keys involved in this factor.
 

Static Protected Attributes

static const int Dim = traits<T>::dimension
 

Friends

class boost::serialization::access
 

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...
 

Constructor & Destructor Documentation

◆ ExpressionFactor() [1/2]

template<typename T >
gtsam::ExpressionFactor< T >::ExpressionFactor ( const SharedNoiseModel noiseModel,
const T &  measurement,
const Expression< T > &  expression 
)
inline

Constructor: creates a factor from a measurement and measurement function.

Parameters
noiseModelthe noise model associated with a measurement
measurementactual value of the measurement, of type T
expressionpredicts the measurement from Values The keys associated with the factor, returned by keys(), are sorted.

◆ ExpressionFactor() [2/2]

template<typename T >
gtsam::ExpressionFactor< T >::ExpressionFactor ( const SharedNoiseModel noiseModel,
const T &  measurement 
)
inlineprotected

Default constructor, for serialization.

Constructor for serializable derived classes

Member Function Documentation

◆ clone()

template<typename T >
gtsam::NonlinearFactor::shared_ptr gtsam::ExpressionFactor< T >::clone ( ) const
inlineoverridevirtual
Returns
a deep copy of this factor

Reimplemented from gtsam::NonlinearFactor.

◆ equals()

template<typename T >
bool gtsam::ExpressionFactor< T >::equals ( const NonlinearFactor f,
double  tol 
) const
inlineoverridevirtual

equals relies on Testable traits being defined for T

Reimplemented from gtsam::NonlinearFactor.

◆ expression()

template<typename T >
virtual Expression< T > gtsam::ExpressionFactor< T >::expression ( ) const
inlineprotectedvirtual

Recreate expression from keys_ and measured_, used in load below.

Needed to deserialize a derived factor

◆ linearize()

template<typename T >
boost::shared_ptr< GaussianFactor > gtsam::ExpressionFactor< T >::linearize ( const Values c) const
inlineoverridevirtual

linearize to a GaussianFactor

Implements gtsam::NonlinearFactor.

◆ print()

template<typename T >
void gtsam::ExpressionFactor< T >::print ( const std::string &  s = "",
const KeyFormatter keyFormatter = DefaultKeyFormatter 
) const
inlineoverridevirtual

print relies on Testable traits being defined for T

Reimplemented from gtsam::Factor.

◆ unwhitenedError()

template<typename T >
Vector gtsam::ExpressionFactor< T >::unwhitenedError ( const Values x,
boost::optional< std::vector< Matrix > & >  H = boost::none 
) const
inlineoverridevirtual

Error function without the NoiseModel, \( z-h(x) -> Local(h(x),z) \).

We override this method to provide both the function evaluation and its derivative(s) in H.

Implements gtsam::NoiseModelFactor.


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