gtsam/gtsam/discrete/DecisionTreeFactor.cpp

139 lines
4.6 KiB
C++

/* ----------------------------------------------------------------------------
* GTSAM Copyright 2010, Georgia Tech Research Corporation,
* Atlanta, Georgia 30332-0415
* All Rights Reserved
* Authors: Frank Dellaert, et al. (see THANKS for the full author list)
* See LICENSE for the license information
* -------------------------------------------------------------------------- */
/**
* @file DecisionTreeFactor.cpp
* @brief discrete factor
* @date Feb 14, 2011
* @author Duy-Nguyen Ta
* @author Frank Dellaert
*/
#include <gtsam/discrete/DecisionTreeFactor.h>
#include <gtsam/discrete/DiscreteConditional.h>
#include <gtsam/base/FastSet.h>
#include <boost/make_shared.hpp>
using namespace std;
namespace gtsam {
/* ******************************************************************************** */
DecisionTreeFactor::DecisionTreeFactor() {
}
/* ******************************************************************************** */
DecisionTreeFactor::DecisionTreeFactor(const DiscreteKeys& keys,
const ADT& potentials) :
DiscreteFactor(keys.indices()), Potentials(keys, potentials) {
}
/* *************************************************************************/
DecisionTreeFactor::DecisionTreeFactor(const DiscreteConditional& c) :
DiscreteFactor(c.keys()), Potentials(c) {
}
/* ************************************************************************* */
bool DecisionTreeFactor::equals(const DiscreteFactor& other, double tol) const {
if(!dynamic_cast<const DecisionTreeFactor*>(&other)) {
return false;
}
else {
const DecisionTreeFactor& f(static_cast<const DecisionTreeFactor&>(other));
return Potentials::equals(f, tol);
}
}
/* ************************************************************************* */
void DecisionTreeFactor::print(const string& s,
const KeyFormatter& formatter) const {
cout << s;
Potentials::print("Potentials:",formatter);
}
/* ************************************************************************* */
DecisionTreeFactor DecisionTreeFactor::apply(const DecisionTreeFactor& f,
ADT::Binary op) const {
map<Key,size_t> cs; // new cardinalities
// make unique key-cardinality map
for(Key j: keys()) cs[j] = cardinality(j);
for(Key j: f.keys()) cs[j] = f.cardinality(j);
// Convert map into keys
DiscreteKeys keys;
for(const std::pair<const Key,size_t>& key: cs)
keys.push_back(key);
// apply operand
ADT result = ADT::apply(f, op);
// Make a new factor
return DecisionTreeFactor(keys, result);
}
/* ************************************************************************* */
DecisionTreeFactor::shared_ptr DecisionTreeFactor::combine(size_t nrFrontals,
ADT::Binary op) const {
if (nrFrontals > size()) throw invalid_argument(
(boost::format(
"DecisionTreeFactor::combine: invalid number of frontal keys %d, nr.keys=%d")
% nrFrontals % size()).str());
// sum over nrFrontals keys
size_t i;
ADT result(*this);
for (i = 0; i < nrFrontals; i++) {
Key j = keys()[i];
result = result.combine(j, cardinality(j), op);
}
// create new factor, note we start keys after nrFrontals
DiscreteKeys dkeys;
for (; i < keys().size(); i++) {
Key j = keys()[i];
dkeys.push_back(DiscreteKey(j,cardinality(j)));
}
return boost::make_shared<DecisionTreeFactor>(dkeys, result);
}
/* ************************************************************************* */
DecisionTreeFactor::shared_ptr DecisionTreeFactor::combine(const Ordering& frontalKeys,
ADT::Binary op) const {
if (frontalKeys.size() > size()) throw invalid_argument(
(boost::format(
"DecisionTreeFactor::combine: invalid number of frontal keys %d, nr.keys=%d")
% frontalKeys.size() % size()).str());
// sum over nrFrontals keys
size_t i;
ADT result(*this);
for (i = 0; i < frontalKeys.size(); i++) {
Key j = frontalKeys[i];
result = result.combine(j, cardinality(j), op);
}
// create new factor, note we collect keys that are not in frontalKeys
// TODO: why do we need this??? result should contain correct keys!!!
DiscreteKeys dkeys;
for (i = 0; i < keys().size(); i++) {
Key j = keys()[i];
// TODO: inefficient!
if (std::find(frontalKeys.begin(), frontalKeys.end(), j) != frontalKeys.end())
continue;
dkeys.push_back(DiscreteKey(j,cardinality(j)));
}
return boost::make_shared<DecisionTreeFactor>(dkeys, result);
}
/* ************************************************************************* */
} // namespace gtsam