gtsam/gtsam/nonlinear/ISAM2-inl.h

250 lines
8.3 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 ISAM2-inl.h
* @brief
* @author Richard Roberts
* @date Mar 16, 2012
*/
#pragma once
#include <stack>
#include <gtsam/inference/FactorGraph.h>
#include <gtsam/linear/JacobianFactor.h>
namespace gtsam {
/* ************************************************************************* */
template<class VALUE>
VALUE ISAM2::calculateEstimate(Key key) const {
const Index index = getOrdering()[key];
const Vector& delta = getDelta()[index];
return theta_.at<VALUE>(key).retract(delta);
}
/* ************************************************************************* */
namespace internal {
template<class CLIQUE>
void optimizeWildfire(const boost::shared_ptr<CLIQUE>& clique, double threshold,
std::vector<bool>& changed, const std::vector<bool>& replaced, VectorValues& delta, int& count) {
// if none of the variables in this clique (frontal and separator!) changed
// significantly, then by the running intersection property, none of the
// cliques in the children need to be processed
// Are any clique variables part of the tree that has been redone?
bool cliqueReplaced = replaced[(*clique)->frontals().front()];
#ifndef NDEBUG
BOOST_FOREACH(Index frontal, (*clique)->frontals()) {
assert(cliqueReplaced == replaced[frontal]);
}
#endif
// If not redone, then has one of the separator variables changed significantly?
bool recalculate = cliqueReplaced;
if(!recalculate) {
BOOST_FOREACH(Index parent, (*clique)->parents()) {
if(changed[parent]) {
recalculate = true;
break;
}
}
}
// Solve clique if it was replaced, or if any parents were changed above the
// threshold or themselves replaced.
if(recalculate) {
// Temporary copy of the original values, to check how much they change
std::vector<Vector> originalValues((*clique)->nrFrontals());
GaussianConditional::const_iterator it;
for(it = (*clique)->beginFrontals(); it!=(*clique)->endFrontals(); it++) {
originalValues[it - (*clique)->beginFrontals()] = delta[*it];
}
// Back-substitute
(*clique)->solveInPlace(delta);
count += (*clique)->nrFrontals();
// Whether the values changed above a threshold, or always true if the
// clique was replaced.
bool valuesChanged = cliqueReplaced;
for(it = (*clique)->beginFrontals(); it!=(*clique)->endFrontals(); it++) {
if(!valuesChanged) {
const Vector& oldValue(originalValues[it - (*clique)->beginFrontals()]);
const SubVector& newValue(delta[*it]);
if((oldValue - newValue).lpNorm<Eigen::Infinity>() >= threshold) {
valuesChanged = true;
break;
}
} else
break;
}
// If the values were above the threshold or this clique was replaced
if(valuesChanged) {
// Set changed flag for each frontal variable and leave the new values
BOOST_FOREACH(Index frontal, (*clique)->frontals()) {
changed[frontal] = true;
}
} else {
// Replace with the old values
for(it = (*clique)->beginFrontals(); it!=(*clique)->endFrontals(); it++) {
delta[*it] = originalValues[it - (*clique)->beginFrontals()];
}
}
// Recurse to children
BOOST_FOREACH(const typename CLIQUE::shared_ptr& child, clique->children_) {
optimizeWildfire(child, threshold, changed, replaced, delta, count);
}
}
}
template<class CLIQUE>
bool optimizeWildfireNode(const boost::shared_ptr<CLIQUE>& clique, double threshold,
std::vector<bool>& changed, const std::vector<bool>& replaced, VectorValues& delta, int& count) {
// if none of the variables in this clique (frontal and separator!) changed
// significantly, then by the running intersection property, none of the
// cliques in the children need to be processed
// Are any clique variables part of the tree that has been redone?
bool cliqueReplaced = replaced[(*clique)->frontals().front()];
#ifndef NDEBUG
BOOST_FOREACH(Index frontal, (*clique)->frontals()) {
assert(cliqueReplaced == replaced[frontal]);
}
#endif
// If not redone, then has one of the separator variables changed significantly?
bool recalculate = cliqueReplaced;
if(!recalculate) {
BOOST_FOREACH(Index parent, (*clique)->parents()) {
if(changed[parent]) {
recalculate = true;
break;
}
}
}
// Solve clique if it was replaced, or if any parents were changed above the
// threshold or themselves replaced.
if(recalculate) {
// Temporary copy of the original values, to check how much they change
std::vector<Vector> originalValues((*clique)->nrFrontals());
GaussianConditional::const_iterator it;
for(it = (*clique)->beginFrontals(); it!=(*clique)->endFrontals(); it++) {
originalValues[it - (*clique)->beginFrontals()] = delta[*it];
}
// Back-substitute
(*clique)->solveInPlace(delta);
count += (*clique)->nrFrontals();
// Whether the values changed above a threshold, or always true if the
// clique was replaced.
bool valuesChanged = cliqueReplaced;
for(it = (*clique)->beginFrontals(); it!=(*clique)->endFrontals(); it++) {
if(!valuesChanged) {
const Vector& oldValue(originalValues[it - (*clique)->beginFrontals()]);
const Vector& newValue(delta[*it]);
if((oldValue - newValue).lpNorm<Eigen::Infinity>() >= threshold) {
valuesChanged = true;
break;
}
} else
break;
}
// If the values were above the threshold or this clique was replaced
if(valuesChanged) {
// Set changed flag for each frontal variable and leave the new values
BOOST_FOREACH(Index frontal, (*clique)->frontals()) {
changed[frontal] = true;
}
} else {
// Replace with the old values
for(it = (*clique)->beginFrontals(); it!=(*clique)->endFrontals(); it++) {
delta[*it] = originalValues[it - (*clique)->beginFrontals()];
}
}
}
return recalculate;
}
} // namespace internal
/* ************************************************************************* */
template<class CLIQUE>
int optimizeWildfire(const boost::shared_ptr<CLIQUE>& root, double threshold, const std::vector<bool>& keys, VectorValues& delta) {
std::vector<bool> changed(keys.size(), false);
int count = 0;
// starting from the root, call optimize on each conditional
if(root)
internal::optimizeWildfire(root, threshold, changed, keys, delta, count);
return count;
}
/* ************************************************************************* */
template<class CLIQUE>
int optimizeWildfireNonRecursive(const boost::shared_ptr<CLIQUE>& root, double threshold, const std::vector<bool>& keys, VectorValues& delta) {
std::vector<bool> changed(keys.size(), false);
int count = 0;
if (root) {
std::stack<boost::shared_ptr<CLIQUE> > travStack;
travStack.push(root);
boost::shared_ptr<CLIQUE> currentNode = root;
while (!travStack.empty()) {
currentNode = travStack.top();
travStack.pop();
bool recalculate = internal::optimizeWildfireNode(currentNode, threshold, changed, keys, delta, count);
if (recalculate) {
BOOST_FOREACH(const typename CLIQUE::shared_ptr& child, currentNode->children_) {
travStack.push(child);
}
}
}
}
return count;
}
/* ************************************************************************* */
template<class CLIQUE>
void nnz_internal(const boost::shared_ptr<CLIQUE>& clique, int& result) {
int dimR = (*clique)->dim();
int dimSep = (*clique)->get_S().cols() - dimR;
result += ((dimR+1)*dimR)/2 + dimSep*dimR;
// traverse the children
BOOST_FOREACH(const typename CLIQUE::shared_ptr& child, clique->children_) {
nnz_internal(child, result);
}
}
/* ************************************************************************* */
template<class CLIQUE>
int calculate_nnz(const boost::shared_ptr<CLIQUE>& clique) {
int result = 0;
// starting from the root, add up entries of frontal and conditional matrices of each conditional
nnz_internal(clique, result);
return result;
}
}