gtsam  4.1.0
gtsam
gtsam::ShonanGaugeFactor Class Reference

Detailed Description

The ShonanGaugeFactor creates a constraint on a single SO(n) to avoid moving in the stabilizer.

Details: SO(p) contains the p*3 Stiefel matrices of orthogonal frames: we take those to be the 3 columns on the left. The P*P skew-symmetric matrices associated with so(p) can be partitioned as (Appendix B in the ECCV paper): | [w] -K' | | K [g] | where w is the SO(3) space, K are the extra Stiefel diemnsions (wormhole!) and (g)amma are extra dimensions in SO(p) that do not modify the cost function. The latter corresponds to rotations SO(p-d), and so the first few values of p-d for d==3 with their corresponding dimensionality are {0:0, 1:0, 2:1, 3:3, ...}

The ShonanGaugeFactor adds a unit Jacobian to these extra dimensions, essentially restricting the optimization to the Stiefel manifold.

+ Inheritance diagram for gtsam::ShonanGaugeFactor:

Public Member Functions

 ShonanGaugeFactor (Key key, size_t p, size_t d=3, boost::optional< double > gamma=boost::none)
 Construct from key for an SO(p) matrix, for base dimension d (2 or 3) If parameter gamma is given, it acts as a precision = 1/sigma^2, and the Jacobian will be multiplied with 1/sigma = sqrt(gamma).
 
virtual ~ShonanGaugeFactor ()
 Destructor.
 
double error (const Values &c) const override
 Calculate the error of the factor: always zero.
 
size_t dim () const override
 get the dimension of the factor (number of rows on linearization)
 
boost::shared_ptr< GaussianFactorlinearize (const Values &c) const override
 linearize to a GaussianFactor
 
- 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 void print (const std::string &s="", const KeyFormatter &keyFormatter=DefaultKeyFormatter) const
 print
 
virtual bool equals (const NonlinearFactor &f, double tol=1e-9) const
 Check if two factors are equal.
 
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 clone () const
 Creates a shared_ptr clone of the factor - needs to be specialized to allow for subclasses. 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 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
 
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
 
KeyVectorkeys ()
 
iterator begin ()
 Iterator at beginning of involved variable keys.
 
iterator end ()
 Iterator at end of involved variable keys.
 

Additional Inherited Members

- 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 inherited from gtsam::NonlinearFactor
typedef Factor Base
 
typedef NonlinearFactor This
 
- 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
 
- 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...
 
- Protected Attributes inherited from gtsam::Factor
KeyVector keys_
 The keys involved in this factor.
 

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