73 lines
2.0 KiB
C++
73 lines
2.0 KiB
C++
/**
|
|
* @file Factor.h
|
|
* @brief A simple factor class to use in a factor graph
|
|
* @brief factor
|
|
* @author Kai Ni
|
|
* @author Frank Dellaert
|
|
*/
|
|
|
|
// \callgraph
|
|
|
|
#pragma once
|
|
|
|
#include <set>
|
|
#include <list>
|
|
#include <boost/utility.hpp> // for noncopyable
|
|
#include "Testable.h"
|
|
|
|
namespace gtsam {
|
|
|
|
/** A combination of a key with a dimension - TODO FD: move, vector specific */
|
|
struct Variable {
|
|
private:
|
|
std::string key_;
|
|
std::size_t dim_;
|
|
public:
|
|
Variable(const std::string& key, std::size_t dim) : key_(key), dim_(dim) {}
|
|
bool operator< (const Variable& other) const {return key_<other.key_; }
|
|
const std::string& key() const { return key_;}
|
|
std::size_t dim() const { return dim_;}
|
|
};
|
|
|
|
/** A set of variables, used to eliminate linear factor factor graphs. TODO FD: move */
|
|
class VariableSet : public std::set<Variable> {
|
|
};
|
|
|
|
/**
|
|
* A simple factor class to use in a factor graph.
|
|
*
|
|
* We make it noncopyable so we enforce the fact that factors are
|
|
* kept in pointer containers. To be safe, you should make them
|
|
* immutable, i.e., practicing functional programming. However, this
|
|
* conflicts with efficiency as well, esp. in the case of incomplete
|
|
* QR factorization. A solution is still being sought.
|
|
*
|
|
* A Factor is templated on a Config, for example VectorConfig is a configuration of
|
|
* labeled vectors. This way, we can have factors that might be defined on discrete
|
|
* variables, continuous ones, or a combination of both. It is up to the config to
|
|
* provide the appropriate values at the appropriate time.
|
|
*/
|
|
template <class Config>
|
|
class Factor : boost::noncopyable, public Testable< Factor<Config> >
|
|
{
|
|
public:
|
|
|
|
virtual ~Factor() {};
|
|
|
|
/**
|
|
* negative log probability
|
|
*/
|
|
virtual double error(const Config& c) const = 0;
|
|
|
|
/**
|
|
* return keys in preferred order
|
|
*/
|
|
virtual std::list<std::string> keys() const = 0;
|
|
|
|
/**
|
|
* @return the number of nodes the factor connects
|
|
*/
|
|
virtual std::size_t size() const = 0;
|
|
};
|
|
}
|