gtsam/cpp/LinearFactor.h

246 lines
6.3 KiB
C++

/**
* @file LinearFactor.h
* @brief Linear Factor....A Gaussian
* @brief linearFactor
* @author Christian Potthast
*/
// \callgraph
#pragma once
#include <list>
#include <map>
#include <set>
#include <ostream>
#include <boost/shared_ptr.hpp>
#include "Matrix.h"
#include "Factor.h"
#include "LinearFactorSet.h"
#include "ConditionalGaussian.h"
#include "Ordering.h"
#define CONSTRUCTOR
namespace gtsam {
class MutableLinearFactor;
/**
* Base Class for a linear factor.
* LinearFactor is non-mutable (all methods const!).
* The factor value is exp(-0.5*||Ax-b||^2)
*/
class LinearFactor: public Factor {
public:
typedef boost::shared_ptr<LinearFactor> shared_ptr;
typedef std::map<std::string, Matrix>::iterator iterator;
typedef std::map<std::string, Matrix>::const_iterator const_iterator;
protected:
std::map<std::string, Matrix> As; // linear matrices
Vector b; // right-hand-side
LinearFactor() {
}
public:
/** Construct Null factor */
CONSTRUCTOR
LinearFactor(const Vector& b_in) :
b(b_in) { //TODO: add a way to initializing base class meaningfully
}
/** Construct unary factor */
CONSTRUCTOR
LinearFactor(const std::string& key1, const Matrix& A1, const Vector& b_in) :
b(b_in) {
As.insert(make_pair(key1, A1));
}
/** Construct binary factor */
CONSTRUCTOR
LinearFactor(const std::string& key1, const Matrix& A1,
const std::string& key2, const Matrix& A2, const Vector& b_in) :
b(b_in) {
As.insert(make_pair(key1, A1));
As.insert(make_pair(key2, A2));
}
/** Construct ternary factor */
CONSTRUCTOR
LinearFactor(const std::string& key1, const Matrix& A1,
const std::string& key2, const Matrix& A2, const std::string& key3,
const Matrix& A3, const Vector& b_in) :
b(b_in) {
As.insert(make_pair(key1, A1));
As.insert(make_pair(key2, A2));
As.insert(make_pair(key3, A3));
}
/** Construct from Conditional Gaussian */
CONSTRUCTOR
LinearFactor(const std::string& key, const boost::shared_ptr<
ConditionalGaussian> cg) :
b(cg->get_d()) {
As.insert(make_pair(key, cg->get_R()));
std::map<std::string, Matrix>::const_iterator it = cg->parentsBegin();
for (; it != cg->parentsEnd(); it++) {
const std::string& j = it->first;
const Matrix& Aj = it->second;
As.insert(make_pair(j, Aj));
}
}
// Implementing Factor virtual functions
double error(const FGConfig& c) const; /** 0.5*(A*x-b)'*(A*x-b) */
void print(const std::string& s = "") const;
bool equals(const Factor& lf, double tol = 1e-9) const;
std::string dump() const { return "";}
std::size_t size() const { return As.size();}
/** STL like, return the iterator pointing to the first node */
const_iterator const begin() const { return As.begin();}
/** STL like, return the iterator pointing to the last node */
const_iterator const end() const { return As.end(); }
/** check if empty */
bool empty() const { return b.size() == 0;}
/** get a copy of b */
const Vector& get_b() const { return b; }
/**
* get a copy of the A matrix from a specific node
* O(log n)
*/
const Matrix& get_A(const std::string& key) const {
const_iterator it = As.find(key);
if (it == As.end())
throw(std::invalid_argument("LinearFactor::[] invalid key: " + key));
return it->second;
}
/** operator[] syntax for get */
inline const Matrix& operator[](const std::string& name) const {
return get_A(name);
}
/** Check if factor involves variable with key */
bool involves(const std::string& key) const {
const_iterator it = As.find(key);
return (it != As.end());
}
/**
* return the number of rows from the b vector
* @return a integer with the number of rows from the b vector
*/
int numberOfRows() const { return b.size();}
/**
* Find all variables and their dimensions
* @return The set of all variable/dimension pairs
*/
VariableSet variables() const;
/**
* Add to separator set if this factor involves key, but don't add key itself
* @param key
* @param separator set to add to
*/
void tally_separator(const std::string& key,
std::set<std::string>& separator) const;
/**
* Return (dense) matrix associated with factor
* @param ordering of variables needed for matrix column order
*/
std::pair<Matrix, Vector> matrix(const Ordering& ordering) const;
}; // LinearFactor
/* ************************************************************************* */
/**
* Mutable subclass of LinearFactor
* To isolate bugs
*/
class MutableLinearFactor: public LinearFactor {
public:
CONSTRUCTOR
MutableLinearFactor() {
}
/**
* Constructor that combines a set of factors
* @param factors Set of factors to combine
*/
CONSTRUCTOR
MutableLinearFactor(const std::set<shared_ptr> & factors);
/** Construct unary mutable factor */
CONSTRUCTOR
MutableLinearFactor(const std::string& key1, const Matrix& A1,
const Vector& b_in) :
LinearFactor(key1, A1, b_in) {
}
/** Construct binary mutable factor */
CONSTRUCTOR
MutableLinearFactor(const std::string& key1, const Matrix& A1,
const std::string& key2, const Matrix& A2, const Vector& b_in) :
LinearFactor(key1, A1, key2, A2, b_in) {
}
/** Construct ternary mutable factor */
CONSTRUCTOR
MutableLinearFactor(const std::string& key1, const Matrix& A1,
const std::string& key2, const Matrix& A2, const std::string& key3,
const Matrix& A3, const Vector& b_in) :
LinearFactor(key1, A1, key2, A2, key3, A3, b_in) {
}
/** insert, copies A */
void insert(const std::string& key, const Matrix& A) {
As.insert(std::make_pair(key, A));
}
/** set RHS, copies b */
void set_b(const Vector& b) {
this->b = b;
}
// set A matrices for the linear factor, same as insert ?
inline void set_A(const std::string& key, const Matrix &A) {
insert(key, A);
}
/**
* eliminate (in place!) one of the variables connected to this factor
* @param key the key of the node to be eliminated
* @return a new factor and a conditional gaussian on the eliminated variable
*/
std::pair<ConditionalGaussian::shared_ptr, shared_ptr> eliminate(
const std::string& key);
/**
* Take the factor f, and append to current matrices. Not very general.
* @param f linear factor graph
* @param m final number of rows of f, needs to be known in advance
* @param pos where to insert in the m-sized matrices
*/
void append_factor(LinearFactor::shared_ptr f, const size_t m,
const size_t pos);
};
} // namespace gtsam