split .h and .cpp for LagoInitializer

release/4.3a0
Luca 2014-05-20 15:49:58 -04:00
parent 569f7bb292
commit 1b5f9e7f02
2 changed files with 282 additions and 242 deletions

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@ -0,0 +1,261 @@
/* ----------------------------------------------------------------------------
* 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 LagoInitializer.h
* @author Luca Carlone
* @author Frank Dellaert
* @date May 14, 2014
*/
#include <gtsam/nonlinear/LagoInitializer.h>
namespace gtsam {
/* ************************************************************************* */
double computeThetaToRoot(const Key nodeKey, const PredecessorMap<Key>& tree,
const key2doubleMap& deltaThetaMap, const key2doubleMap& thetaFromRootMap) {
double nodeTheta = 0;
Key key_child = nodeKey; // the node
Key key_parent = 0; // the initialization does not matter
while(1){
// We check if we reached the root
if(tree.at(key_child)==key_child) // if we reached the root
break;
// we sum the delta theta corresponding to the edge parent->child
nodeTheta += deltaThetaMap.at(key_child);
// we get the parent
key_parent = tree.at(key_child); // the parent
// we check if we connected to some part of the tree we know
if(thetaFromRootMap.find(key_parent)!=thetaFromRootMap.end()){
nodeTheta += thetaFromRootMap.at(key_parent);
break;
}
key_child = key_parent; // we move upwards in the tree
}
return nodeTheta;
}
/* ************************************************************************* */
key2doubleMap computeThetasToRoot(const key2doubleMap& deltaThetaMap,
const PredecessorMap<Key>& tree) {
key2doubleMap thetaToRootMap;
key2doubleMap::const_iterator it;
// for all nodes in the tree
for(it = deltaThetaMap.begin(); it != deltaThetaMap.end(); ++it ){
// compute the orientation wrt root
Key nodeKey = it->first;
double nodeTheta = computeThetaToRoot(nodeKey, tree, deltaThetaMap,
thetaToRootMap);
thetaToRootMap.insert(std::pair<Key, double>(nodeKey, nodeTheta));
}
return thetaToRootMap;
}
/* ************************************************************************* */
void getSymbolicGraph(
/*OUTPUTS*/ std::vector<size_t>& spanningTreeIds, std::vector<size_t>& chordsIds, key2doubleMap& deltaThetaMap,
/*INPUTS*/ const PredecessorMap<Key>& tree, const NonlinearFactorGraph& g){
// Get keys for which you want the orientation
size_t id=0;
// Loop over the factors
BOOST_FOREACH(const boost::shared_ptr<NonlinearFactor>& factor, g){
if (factor->keys().size() == 2){
Key key1 = factor->keys()[0];
Key key2 = factor->keys()[1];
// recast to a between
boost::shared_ptr< BetweenFactor<Pose2> > pose2Between =
boost::dynamic_pointer_cast< BetweenFactor<Pose2> >(factor);
if (!pose2Between) continue;
// get the orientation - measured().theta();
double deltaTheta = pose2Between->measured().theta();
// insert (directed) orientations in the map "deltaThetaMap"
bool inTree=false;
if(tree.at(key1)==key2){
deltaThetaMap.insert(std::pair<Key, double>(key1, -deltaTheta));
inTree = true;
} else if(tree.at(key2)==key1){
deltaThetaMap.insert(std::pair<Key, double>(key2, deltaTheta));
inTree = true;
}
// store factor slot, distinguishing spanning tree edges from chordsIds
if(inTree == true)
spanningTreeIds.push_back(id);
else // it's a chord!
chordsIds.push_back(id);
}
id++;
}
}
/* ************************************************************************* */
void getDeltaThetaAndNoise(NonlinearFactor::shared_ptr factor,
Vector& deltaTheta, noiseModel::Diagonal::shared_ptr& model_deltaTheta) {
// Get the relative rotation measurement from the between factor
boost::shared_ptr<BetweenFactor<Pose2> > pose2Between =
boost::dynamic_pointer_cast<BetweenFactor<Pose2> >(factor);
if (!pose2Between)
throw std::invalid_argument("buildLinearOrientationGraph: invalid between factor!");
deltaTheta = (Vector(1) << pose2Between->measured().theta());
// Retrieve the noise model for the relative rotation
SharedNoiseModel model = pose2Between->get_noiseModel();
boost::shared_ptr<noiseModel::Diagonal> diagonalModel =
boost::dynamic_pointer_cast<noiseModel::Diagonal>(model);
if (!diagonalModel)
throw std::invalid_argument("buildLinearOrientationGraph: invalid noise model "
"(current version assumes diagonal noise model)!");
Vector std_deltaTheta = (Vector(1) << diagonalModel->sigma(2) ); // std on the angular measurement
model_deltaTheta = noiseModel::Diagonal::Sigmas(std_deltaTheta);
}
/* ************************************************************************* */
GaussianFactorGraph buildLinearOrientationGraph(const std::vector<size_t>& spanningTreeIds, const std::vector<size_t>& chordsIds,
const NonlinearFactorGraph& g, const key2doubleMap& orientationsToRoot, const PredecessorMap<Key>& tree){
GaussianFactorGraph lagoGraph;
Vector deltaTheta;
noiseModel::Diagonal::shared_ptr model_deltaTheta;
Matrix I = eye(1);
// put original measurements in the spanning tree
BOOST_FOREACH(const size_t& factorId, spanningTreeIds){
const FastVector<Key>& keys = g[factorId]->keys();
Key key1 = keys[0], key2 = keys[1];
getDeltaThetaAndNoise(g[factorId], deltaTheta, model_deltaTheta);
lagoGraph.add(JacobianFactor(key1, -I, key2, I, deltaTheta, model_deltaTheta));
}
// put regularized measurements in the chordsIds
BOOST_FOREACH(const size_t& factorId, chordsIds){
const FastVector<Key>& keys = g[factorId]->keys();
Key key1 = keys[0], key2 = keys[1];
getDeltaThetaAndNoise(g[factorId], deltaTheta, model_deltaTheta);
double key1_DeltaTheta_key2 = deltaTheta(0);
double k2pi_noise = key1_DeltaTheta_key2 + orientationsToRoot.at(key1) - orientationsToRoot.at(key2); // this coincides to summing up measurements along the cycle induced by the chord
double k = round(k2pi_noise/(2*M_PI));
Vector deltaThetaRegularized = (Vector(1) << key1_DeltaTheta_key2 - 2*k*M_PI);
lagoGraph.add(JacobianFactor(key1, -I, key2, I, deltaThetaRegularized, model_deltaTheta));
}
// prior on the anchor orientation
lagoGraph.add(JacobianFactor(keyAnchor, I, (Vector(1) << 0.0), priorOrientationNoise));
return lagoGraph;
}
/* ************************************************************************* */
NonlinearFactorGraph buildPose2graph(const NonlinearFactorGraph& graph){
NonlinearFactorGraph pose2Graph;
BOOST_FOREACH(const boost::shared_ptr<NonlinearFactor>& factor, graph){
// recast to a between on Pose2
boost::shared_ptr< BetweenFactor<Pose2> > pose2Between =
boost::dynamic_pointer_cast< BetweenFactor<Pose2> >(factor);
if (pose2Between)
pose2Graph.add(pose2Between);
// recast PriorFactor<Pose2> to BetweenFactor<Pose2>
boost::shared_ptr< PriorFactor<Pose2> > pose2Prior =
boost::dynamic_pointer_cast< PriorFactor<Pose2> >(factor);
if (pose2Prior)
pose2Graph.add(BetweenFactor<Pose2>(keyAnchor, pose2Prior->keys()[0],
pose2Prior->prior(), pose2Prior->get_noiseModel()));
}
return pose2Graph;
}
/* ************************************************************************* */
VectorValues computeLagoOrientations(const NonlinearFactorGraph& pose2Graph){
// Find a minimum spanning tree
PredecessorMap<Key> tree = findMinimumSpanningTree<NonlinearFactorGraph, Key, BetweenFactor<Pose2> >(pose2Graph);
// Create a linear factor graph (LFG) of scalars
key2doubleMap deltaThetaMap;
std::vector<size_t> spanningTreeIds; // ids of between factors forming the spanning tree T
std::vector<size_t> chordsIds; // ids of between factors corresponding to chordsIds wrt T
getSymbolicGraph(spanningTreeIds, chordsIds, deltaThetaMap, tree, pose2Graph);
// temporary structure to correct wraparounds along loops
key2doubleMap orientationsToRoot = computeThetasToRoot(deltaThetaMap, tree);
// regularize measurements and plug everything in a factor graph
GaussianFactorGraph lagoGraph = buildLinearOrientationGraph(spanningTreeIds, chordsIds, pose2Graph, orientationsToRoot, tree);
// Solve the LFG
VectorValues orientationsLago = lagoGraph.optimize();
return orientationsLago;
}
/* ************************************************************************* */
VectorValues initializeOrientationsLago(const NonlinearFactorGraph& graph) {
// We "extract" the Pose2 subgraph of the original graph: this
// is done to properly model priors and avoiding operating on a larger graph
NonlinearFactorGraph pose2Graph = buildPose2graph(graph);
// Get orientations from relative orientation measurements
return computeLagoOrientations(pose2Graph);
}
/* ************************************************************************* */
Values initializeLago(const NonlinearFactorGraph& graph) {
// We "extract" the Pose2 subgraph of the original graph: this
// is done to properly model priors and avoiding operating on a larger graph
NonlinearFactorGraph pose2Graph = buildPose2graph(graph);
// Get orientations from relative orientation measurements
VectorValues orientationsLago = computeLagoOrientations(pose2Graph);
Values initialGuessLago;
// for all nodes in the tree
for(VectorValues::const_iterator it = orientationsLago.begin(); it != orientationsLago.end(); ++it ){
Key key = it->first;
Vector orientation = orientationsLago.at(key);
Pose2 poseLago = Pose2(0.0,0.0,orientation(0));
initialGuessLago.insert(key, poseLago);
}
// add prior needed by GN
pose2Graph.add(PriorFactor<Pose2>(keyAnchor, Pose2(), priorPose2Noise));
// Optimize Pose2, with initialGuessLago as initial guess
GaussNewtonOptimizer pose2optimizer(pose2Graph, initialGuessLago);
initialGuessLago = pose2optimizer.optimize();
initialGuessLago.erase(keyAnchor); // that was fictitious
return initialGuessLago;
}
/* ************************************************************************* */
Values initializeLago(const NonlinearFactorGraph& graph, const Values& initialGuess) {
Values initialGuessLago;
// get the orientation estimates from LAGO
VectorValues orientations = initializeOrientationsLago(graph);
// for all nodes in the tree
for(VectorValues::const_iterator it = orientations.begin(); it != orientations.end(); ++it ){
Key key = it->first;
if (key != keyAnchor){
Pose2 pose = initialGuess.at<Pose2>(key);
Vector orientation = orientations.at(key);
Pose2 poseLago = Pose2(pose.x(),pose.y(),orientation(0));
initialGuessLago.insert(key, poseLago);
}
}
return initialGuessLago;
}
} // end of namespace gtsam

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@ -10,7 +10,7 @@
* -------------------------------------------------------------------------- */ * -------------------------------------------------------------------------- */
/** /**
* @file testPlanarSLAMExample_lago.cpp * @file LagoInitializer.h
* @brief Initialize Pose2 in a factor graph using LAGO * @brief Initialize Pose2 in a factor graph using LAGO
* (Linear Approximation for Graph Optimization). see papers: * (Linear Approximation for Graph Optimization). see papers:
* *
@ -48,271 +48,50 @@ const Key keyAnchor = symbol('Z',9999999);
noiseModel::Diagonal::shared_ptr priorOrientationNoise = noiseModel::Diagonal::Variances((Vector(1) << 1e-8)); noiseModel::Diagonal::shared_ptr priorOrientationNoise = noiseModel::Diagonal::Variances((Vector(1) << 1e-8));
noiseModel::Diagonal::shared_ptr priorPose2Noise = noiseModel::Diagonal::Variances((Vector(3) << 1e-6, 1e-6, 1e-8)); noiseModel::Diagonal::shared_ptr priorPose2Noise = noiseModel::Diagonal::Variances((Vector(3) << 1e-6, 1e-6, 1e-8));
/* /* This function computes the cumulative orientation (without wrapping) wrt the root of a spanning tree (tree)
* This function computes the cumulative orientation (without wrapping) wrt the root of a spanning tree (tree)
* for a node (nodeKey). The function starts at the nodes and moves towards the root * for a node (nodeKey). The function starts at the nodes and moves towards the root
* summing up the (directed) rotation measurements. Relative measurements are encoded in "deltaThetaMap" * summing up the (directed) rotation measurements. Relative measurements are encoded in "deltaThetaMap"
* The root is assumed to have orientation zero. * The root is assumed to have orientation zero.
*/ */
double computeThetaToRoot(const Key nodeKey, const PredecessorMap<Key>& tree, double computeThetaToRoot(const Key nodeKey, const PredecessorMap<Key>& tree,
const key2doubleMap& deltaThetaMap, const key2doubleMap& thetaFromRootMap) { const key2doubleMap& deltaThetaMap, const key2doubleMap& thetaFromRootMap);
double nodeTheta = 0; /* This function computes the cumulative orientations (without wrapping)
Key key_child = nodeKey; // the node
Key key_parent = 0; // the initialization does not matter
while(1){
// We check if we reached the root
if(tree.at(key_child)==key_child) // if we reached the root
break;
// we sum the delta theta corresponding to the edge parent->child
nodeTheta += deltaThetaMap.at(key_child);
// we get the parent
key_parent = tree.at(key_child); // the parent
// we check if we connected to some part of the tree we know
if(thetaFromRootMap.find(key_parent)!=thetaFromRootMap.end()){
nodeTheta += thetaFromRootMap.at(key_parent);
break;
}
key_child = key_parent; // we move upwards in the tree
}
return nodeTheta;
}
/*
* This function computes the cumulative orientations (without wrapping)
* for all node wrt the root (root has zero orientation) * for all node wrt the root (root has zero orientation)
*/ */
key2doubleMap computeThetasToRoot(const key2doubleMap& deltaThetaMap, key2doubleMap computeThetasToRoot(const key2doubleMap& deltaThetaMap,
const PredecessorMap<Key>& tree) { const PredecessorMap<Key>& tree);
key2doubleMap thetaToRootMap; /* Given a factor graph "g", and a spanning tree "tree", the function selects the nodes belonging to the tree and to g,
key2doubleMap::const_iterator it;
// for all nodes in the tree
for(it = deltaThetaMap.begin(); it != deltaThetaMap.end(); ++it )
{
// compute the orientation wrt root
Key nodeKey = it->first;
double nodeTheta = computeThetaToRoot(nodeKey, tree, deltaThetaMap,
thetaToRootMap);
thetaToRootMap.insert(std::pair<Key, double>(nodeKey, nodeTheta));
}
return thetaToRootMap;
}
/*
* Given a factor graph "g", and a spanning tree "tree", the function selects the nodes belonging to the tree and to g,
* and stores the factor slots corresponding to edges in the tree and to chordsIds wrt this tree * and stores the factor slots corresponding to edges in the tree and to chordsIds wrt this tree
* Also it computes deltaThetaMap which is a fast way to encode relative orientations along the tree: * Also it computes deltaThetaMap which is a fast way to encode relative orientations along the tree:
* for a node key2, s.t. tree[key2]=key1, the values deltaThetaMap[key2] is the relative orientation theta[key2]-theta[key1] * for a node key2, s.t. tree[key2]=key1, the values deltaThetaMap[key2] is the relative orientation theta[key2]-theta[key1]
*/ */
void getSymbolicGraph( void getSymbolicGraph(
/*OUTPUTS*/ std::vector<size_t>& spanningTreeIds, std::vector<size_t>& chordsIds, key2doubleMap& deltaThetaMap, /*OUTPUTS*/ std::vector<size_t>& spanningTreeIds, std::vector<size_t>& chordsIds, key2doubleMap& deltaThetaMap,
/*INPUTS*/ const PredecessorMap<Key>& tree, const NonlinearFactorGraph& g){ /*INPUTS*/ const PredecessorMap<Key>& tree, const NonlinearFactorGraph& g);
// Get keys for which you want the orientation /* Retrieves the deltaTheta and the corresponding noise model from a BetweenFactor<Pose2> */
size_t id=0;
// Loop over the factors
BOOST_FOREACH(const boost::shared_ptr<NonlinearFactor>& factor, g){
if (factor->keys().size() == 2){
Key key1 = factor->keys()[0];
Key key2 = factor->keys()[1];
// recast to a between
boost::shared_ptr< BetweenFactor<Pose2> > pose2Between =
boost::dynamic_pointer_cast< BetweenFactor<Pose2> >(factor);
if (!pose2Between) continue;
// get the orientation - measured().theta();
double deltaTheta = pose2Between->measured().theta();
// insert (directed) orientations in the map "deltaThetaMap"
bool inTree=false;
if(tree.at(key1)==key2){
deltaThetaMap.insert(std::pair<Key, double>(key1, -deltaTheta));
inTree = true;
} else if(tree.at(key2)==key1){
deltaThetaMap.insert(std::pair<Key, double>(key2, deltaTheta));
inTree = true;
}
// store factor slot, distinguishing spanning tree edges from chordsIds
if(inTree == true)
spanningTreeIds.push_back(id);
else // it's a chord!
chordsIds.push_back(id);
}
id++;
}
}
/*
* Retrieves the deltaTheta and the corresponding noise model from a BetweenFactor<Pose2>
*/
void getDeltaThetaAndNoise(NonlinearFactor::shared_ptr factor, void getDeltaThetaAndNoise(NonlinearFactor::shared_ptr factor,
Vector& deltaTheta, noiseModel::Diagonal::shared_ptr& model_deltaTheta) { Vector& deltaTheta, noiseModel::Diagonal::shared_ptr& model_deltaTheta);
// Get the relative rotation measurement from the between factor /* Linear factor graph with regularized orientation measurements */
boost::shared_ptr<BetweenFactor<Pose2> > pose2Between =
boost::dynamic_pointer_cast<BetweenFactor<Pose2> >(factor);
if (!pose2Between)
throw std::invalid_argument("buildLinearOrientationGraph: invalid between factor!");
deltaTheta = (Vector(1) << pose2Between->measured().theta());
// Retrieve the noise model for the relative rotation
SharedNoiseModel model = pose2Between->get_noiseModel();
boost::shared_ptr<noiseModel::Diagonal> diagonalModel =
boost::dynamic_pointer_cast<noiseModel::Diagonal>(model);
if (!diagonalModel)
throw std::invalid_argument("buildLinearOrientationGraph: invalid noise model "
"(current version assumes diagonal noise model)!");
Vector std_deltaTheta = (Vector(1) << diagonalModel->sigma(2) ); // std on the angular measurement
model_deltaTheta = noiseModel::Diagonal::Sigmas(std_deltaTheta);
}
/*
* Linear factor graph with regularized orientation measurements
*/
GaussianFactorGraph buildLinearOrientationGraph(const std::vector<size_t>& spanningTreeIds, const std::vector<size_t>& chordsIds, GaussianFactorGraph buildLinearOrientationGraph(const std::vector<size_t>& spanningTreeIds, const std::vector<size_t>& chordsIds,
const NonlinearFactorGraph& g, const key2doubleMap& orientationsToRoot, const PredecessorMap<Key>& tree){ const NonlinearFactorGraph& g, const key2doubleMap& orientationsToRoot, const PredecessorMap<Key>& tree);
GaussianFactorGraph lagoGraph; /* Selects the subgraph of betweenFactors and transforms priors into between wrt a fictitious node */
Vector deltaTheta; NonlinearFactorGraph buildPose2graph(const NonlinearFactorGraph& graph);
noiseModel::Diagonal::shared_ptr model_deltaTheta;
Matrix I = eye(1); /* Returns the orientations of a graph including only BetweenFactors<Pose2> */
// put original measurements in the spanning tree VectorValues computeLagoOrientations(const NonlinearFactorGraph& pose2Graph);
BOOST_FOREACH(const size_t& factorId, spanningTreeIds){
const FastVector<Key>& keys = g[factorId]->keys();
Key key1 = keys[0], key2 = keys[1];
getDeltaThetaAndNoise(g[factorId], deltaTheta, model_deltaTheta);
lagoGraph.add(JacobianFactor(key1, -I, key2, I, deltaTheta, model_deltaTheta));
}
// put regularized measurements in the chordsIds
BOOST_FOREACH(const size_t& factorId, chordsIds){
const FastVector<Key>& keys = g[factorId]->keys();
Key key1 = keys[0], key2 = keys[1];
getDeltaThetaAndNoise(g[factorId], deltaTheta, model_deltaTheta);
double key1_DeltaTheta_key2 = deltaTheta(0);
double k2pi_noise = key1_DeltaTheta_key2 + orientationsToRoot.at(key1) - orientationsToRoot.at(key2); // this coincides to summing up measurements along the cycle induced by the chord
double k = round(k2pi_noise/(2*M_PI));
Vector deltaThetaRegularized = (Vector(1) << key1_DeltaTheta_key2 - 2*k*M_PI);
lagoGraph.add(JacobianFactor(key1, -I, key2, I, deltaThetaRegularized, model_deltaTheta));
}
// prior on the anchor orientation
lagoGraph.add(JacobianFactor(keyAnchor, I, (Vector(1) << 0.0), priorOrientationNoise));
return lagoGraph;
}
/* /* LAGO: Returns the orientations of the Pose2 in a generic factor graph */
* Selects the subgraph of betweenFactors and transforms priors into between wrt a fictitious node VectorValues initializeOrientationsLago(const NonlinearFactorGraph& graph);
*/
NonlinearFactorGraph buildPose2graph(const NonlinearFactorGraph& graph){
NonlinearFactorGraph pose2Graph;
BOOST_FOREACH(const boost::shared_ptr<NonlinearFactor>& factor, graph){ /* Returns the values for the Pose2 in a generic factor graph */
Values initializeLago(const NonlinearFactorGraph& graph);
// recast to a between on Pose2 /* Only corrects the orientation part in initialGuess */
boost::shared_ptr< BetweenFactor<Pose2> > pose2Between = Values initializeLago(const NonlinearFactorGraph& graph, const Values& initialGuess);
boost::dynamic_pointer_cast< BetweenFactor<Pose2> >(factor);
if (pose2Between)
pose2Graph.add(pose2Between);
// recast PriorFactor<Pose2> to BetweenFactor<Pose2>
boost::shared_ptr< PriorFactor<Pose2> > pose2Prior =
boost::dynamic_pointer_cast< PriorFactor<Pose2> >(factor);
if (pose2Prior)
pose2Graph.add(BetweenFactor<Pose2>(keyAnchor, pose2Prior->keys()[0],
pose2Prior->prior(), pose2Prior->get_noiseModel()));
}
return pose2Graph;
}
/*
* Returns the orientations of a graph including only BetweenFactors<Pose2>
*/
VectorValues computeLagoOrientations(const NonlinearFactorGraph& pose2Graph){
// Find a minimum spanning tree
PredecessorMap<Key> tree = findMinimumSpanningTree<NonlinearFactorGraph, Key, BetweenFactor<Pose2> >(pose2Graph);
// Create a linear factor graph (LFG) of scalars
key2doubleMap deltaThetaMap;
std::vector<size_t> spanningTreeIds; // ids of between factors forming the spanning tree T
std::vector<size_t> chordsIds; // ids of between factors corresponding to chordsIds wrt T
getSymbolicGraph(spanningTreeIds, chordsIds, deltaThetaMap, tree, pose2Graph);
// temporary structure to correct wraparounds along loops
key2doubleMap orientationsToRoot = computeThetasToRoot(deltaThetaMap, tree);
// regularize measurements and plug everything in a factor graph
GaussianFactorGraph lagoGraph = buildLinearOrientationGraph(spanningTreeIds, chordsIds, pose2Graph, orientationsToRoot, tree);
// Solve the LFG
VectorValues orientationsLago = lagoGraph.optimize();
return orientationsLago;
}
/*
* Returns the orientations of the Pose2 in a generic factor graph
*/
VectorValues initializeOrientationsLago(const NonlinearFactorGraph& graph) {
// We "extract" the Pose2 subgraph of the original graph: this
// is done to properly model priors and avoiding operating on a larger graph
NonlinearFactorGraph pose2Graph = buildPose2graph(graph);
// Get orientations from relative orientation measurements
return computeLagoOrientations(pose2Graph);
}
/*
* Returns the values for the Pose2 in a generic factor graph
*/
Values initializeLago(const NonlinearFactorGraph& graph) {
// We "extract" the Pose2 subgraph of the original graph: this
// is done to properly model priors and avoiding operating on a larger graph
NonlinearFactorGraph pose2Graph = buildPose2graph(graph);
// Get orientations from relative orientation measurements
VectorValues orientationsLago = computeLagoOrientations(pose2Graph);
Values initialGuessLago;
// for all nodes in the tree
for(VectorValues::const_iterator it = orientationsLago.begin(); it != orientationsLago.end(); ++it ){
Key key = it->first;
Vector orientation = orientationsLago.at(key);
Pose2 poseLago = Pose2(0.0,0.0,orientation(0));
initialGuessLago.insert(key, poseLago);
}
pose2Graph.add(PriorFactor<Pose2>(keyAnchor, Pose2(), priorPose2Noise));
GaussNewtonOptimizer pose2optimizer(pose2Graph, initialGuessLago);
initialGuessLago = pose2optimizer.optimize();
initialGuessLago.erase(keyAnchor); // that was fictitious
return initialGuessLago;
}
/*
* Only corrects the orientation part in initialGuess
*/
Values initializeLago(const NonlinearFactorGraph& graph, const Values& initialGuess) {
Values initialGuessLago;
// get the orientation estimates from LAGO
VectorValues orientations = initializeOrientationsLago(graph);
// for all nodes in the tree
for(VectorValues::const_iterator it = orientations.begin(); it != orientations.end(); ++it ){
Key key = it->first;
if (key != keyAnchor){
Pose2 pose = initialGuess.at<Pose2>(key);
Vector orientation = orientations.at(key);
Pose2 poseLago = Pose2(pose.x(),pose.y(),orientation(0));
initialGuessLago.insert(key, poseLago);
}
}
return initialGuessLago;
}
} // end of namespace gtsam } // end of namespace gtsam