gtsam/tests/testGaussianISAM.cpp

389 lines
15 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 testGaussianISAM.cpp
* @brief Unit tests for GaussianISAM
* @author Michael Kaess
*/
#include <tests/smallExample.h>
#include <gtsam/nonlinear/Ordering.h>
#include <gtsam/nonlinear/Symbol.h>
#include <gtsam/linear/GaussianBayesNet.h>
#include <gtsam/linear/GaussianISAM.h>
#include <gtsam/linear/GaussianSequentialSolver.h>
#include <gtsam/linear/GaussianMultifrontalSolver.h>
#include <gtsam/inference/ISAM.h>
#include <gtsam/geometry/Rot2.h>
#include <CppUnitLite/TestHarness.h>
#include <boost/foreach.hpp>
#include <boost/assign/std/list.hpp> // for operator +=
using namespace boost::assign;
using namespace std;
using namespace gtsam;
using namespace example;
using symbol_shorthand::X;
using symbol_shorthand::L;
/* ************************************************************************* */
// Some numbers that should be consistent among all smoother tests
double sigmax1 = 0.786153, sigmax2 = 1.0/1.47292, sigmax3 = 0.671512, sigmax4 =
0.669534, sigmax5 = sigmax3, sigmax6 = sigmax2, sigmax7 = sigmax1;
const double tol = 1e-4;
/* ************************************************************************* */
TEST_UNSAFE( ISAM, iSAM_smoother )
{
Ordering ordering;
for (int t = 1; t <= 7; t++) ordering += X(t);
// Create smoother with 7 nodes
GaussianFactorGraph smoother = createSmoother(7, ordering).first;
// run iSAM for every factor
GaussianISAM actual;
BOOST_FOREACH(boost::shared_ptr<GaussianFactor> factor, smoother) {
GaussianFactorGraph factorGraph;
factorGraph.push_back(factor);
actual.update(factorGraph);
}
BayesTree<GaussianConditional>::shared_ptr bayesTree = GaussianMultifrontalSolver(smoother).eliminate();
// Create expected Bayes Tree by solving smoother with "natural" ordering
GaussianISAM expected(*bayesTree);
// Check whether BayesTree is correct
EXPECT(assert_equal(expected, actual));
// obtain solution
VectorValues e(VectorValues::Zero(7,2)); // expected solution
VectorValues optimized = optimize(actual); // actual solution
EXPECT(assert_equal(e, optimized));
}
/* ************************************************************************* */
// SL-FIX TEST( ISAM, iSAM_smoother2 )
//{
// // Create smoother with 7 nodes
// GaussianFactorGraph smoother = createSmoother(7);
//
// // Create initial tree from first 4 timestamps in reverse order !
// Ordering ord; ord += X(4),X(3),X(2),X(1);
// GaussianFactorGraph factors1;
// for (int i=0;i<7;i++) factors1.push_back(smoother[i]);
// GaussianISAM actual(*inference::Eliminate(factors1));
//
// // run iSAM with remaining factors
// GaussianFactorGraph factors2;
// for (int i=7;i<13;i++) factors2.push_back(smoother[i]);
// actual.update(factors2);
//
// // Create expected Bayes Tree by solving smoother with "natural" ordering
// Ordering ordering;
// for (int t = 1; t <= 7; t++) ordering += symbol('x', t);
// GaussianISAM expected(smoother.eliminate(ordering));
//
// EXPECT(assert_equal(expected, actual));
//}
/* ************************************************************************* *
Bayes tree for smoother with "natural" ordering:
C1 x6 x7
C2 x5 : x6
C3 x4 : x5
C4 x3 : x4
C5 x2 : x3
C6 x1 : x2
**************************************************************************** */
TEST_UNSAFE( BayesTree, linear_smoother_shortcuts )
{
// Create smoother with 7 nodes
Ordering ordering;
GaussianFactorGraph smoother;
boost::tie(smoother, ordering) = createSmoother(7);
BayesTree<GaussianConditional> bayesTree = *GaussianMultifrontalSolver(smoother).eliminate();
// Create the Bayes tree
GaussianISAM isamTree(bayesTree);
LONGS_EQUAL(6,isamTree.size());
// Check the conditional P(Root|Root)
GaussianBayesNet empty;
GaussianISAM::sharedClique R = isamTree.root();
GaussianBayesNet actual1 = GaussianISAM::shortcut(R,R);
EXPECT(assert_equal(empty,actual1,tol));
// Check the conditional P(C2|Root)
GaussianISAM::sharedClique C2 = isamTree[ordering[X(5)]];
GaussianBayesNet actual2 = GaussianISAM::shortcut(C2,R);
EXPECT(assert_equal(empty,actual2,tol));
// Check the conditional P(C3|Root)
double sigma3 = 0.61808;
Matrix A56 = Matrix_(2,2,-0.382022,0.,0.,-0.382022);
GaussianBayesNet expected3;
push_front(expected3,ordering[X(5)], zero(2), eye(2)/sigma3, ordering[X(6)], A56/sigma3, ones(2));
GaussianISAM::sharedClique C3 = isamTree[ordering[X(4)]];
GaussianBayesNet actual3 = GaussianISAM::shortcut(C3,R);
EXPECT(assert_equal(expected3,actual3,tol));
// Check the conditional P(C4|Root)
double sigma4 = 0.661968;
Matrix A46 = Matrix_(2,2,-0.146067,0.,0.,-0.146067);
GaussianBayesNet expected4;
push_front(expected4, ordering[X(4)], zero(2), eye(2)/sigma4, ordering[X(6)], A46/sigma4, ones(2));
GaussianISAM::sharedClique C4 = isamTree[ordering[X(3)]];
GaussianBayesNet actual4 = GaussianISAM::shortcut(C4,R);
EXPECT(assert_equal(expected4,actual4,tol));
}
/* ************************************************************************* *
Bayes tree for smoother with "nested dissection" ordering:
Node[x1] P(x1 | x2)
Node[x3] P(x3 | x2 x4)
Node[x5] P(x5 | x4 x6)
Node[x7] P(x7 | x6)
Node[x2] P(x2 | x4)
Node[x6] P(x6 | x4)
Node[x4] P(x4)
becomes
C1 x5 x6 x4
C2 x3 x2 : x4
C3 x1 : x2
C4 x7 : x6
************************************************************************* */
TEST_UNSAFE( BayesTree, balanced_smoother_marginals )
{
// Create smoother with 7 nodes
Ordering ordering;
ordering += X(1),X(3),X(5),X(7),X(2),X(6),X(4);
GaussianFactorGraph smoother = createSmoother(7, ordering).first;
// Create the Bayes tree
BayesTree<GaussianConditional> chordalBayesNet = *GaussianMultifrontalSolver(smoother).eliminate();
VectorValues expectedSolution(VectorValues::Zero(7,2));
VectorValues actualSolution = optimize(chordalBayesNet);
EXPECT(assert_equal(expectedSolution,actualSolution,tol));
// Create the Bayes tree
GaussianISAM bayesTree(chordalBayesNet);
LONGS_EQUAL(4,bayesTree.size());
double tol=1e-5;
// Check marginal on x1
GaussianBayesNet expected1 = simpleGaussian(ordering[X(1)], zero(2), sigmax1);
GaussianBayesNet actual1 = *bayesTree.marginalBayesNet(ordering[X(1)]);
Matrix expectedCovarianceX1 = eye(2,2) * (sigmax1 * sigmax1);
Matrix actualCovarianceX1;
actualCovarianceX1 = bayesTree.marginalCovariance(ordering[X(1)]);
EXPECT(assert_equal(expectedCovarianceX1, actualCovarianceX1, tol));
EXPECT(assert_equal(expected1,actual1,tol));
// Check marginal on x2
double sigx2 = 0.68712938; // FIXME: this should be corrected analytically
GaussianBayesNet expected2 = simpleGaussian(ordering[X(2)], zero(2), sigx2);
GaussianBayesNet actual2 = *bayesTree.marginalBayesNet(ordering[X(2)]);
Matrix expectedCovarianceX2 = eye(2,2) * (sigx2 * sigx2);
Matrix actualCovarianceX2;
actualCovarianceX2 = bayesTree.marginalCovariance(ordering[X(2)]);
EXPECT(assert_equal(expectedCovarianceX2, actualCovarianceX2, tol));
EXPECT(assert_equal(expected2,actual2,tol));
// Check marginal on x3
GaussianBayesNet expected3 = simpleGaussian(ordering[X(3)], zero(2), sigmax3);
GaussianBayesNet actual3 = *bayesTree.marginalBayesNet(ordering[X(3)]);
Matrix expectedCovarianceX3 = eye(2,2) * (sigmax3 * sigmax3);
Matrix actualCovarianceX3;
actualCovarianceX3 = bayesTree.marginalCovariance(ordering[X(3)]);
EXPECT(assert_equal(expectedCovarianceX3, actualCovarianceX3, tol));
EXPECT(assert_equal(expected3,actual3,tol));
// Check marginal on x4
GaussianBayesNet expected4 = simpleGaussian(ordering[X(4)], zero(2), sigmax4);
GaussianBayesNet actual4 = *bayesTree.marginalBayesNet(ordering[X(4)]);
Matrix expectedCovarianceX4 = eye(2,2) * (sigmax4 * sigmax4);
Matrix actualCovarianceX4;
actualCovarianceX4 = bayesTree.marginalCovariance(ordering[X(4)]);
EXPECT(assert_equal(expectedCovarianceX4, actualCovarianceX4, tol));
EXPECT(assert_equal(expected4,actual4,tol));
// Check marginal on x7 (should be equal to x1)
GaussianBayesNet expected7 = simpleGaussian(ordering[X(7)], zero(2), sigmax7);
GaussianBayesNet actual7 = *bayesTree.marginalBayesNet(ordering[X(7)]);
Matrix expectedCovarianceX7 = eye(2,2) * (sigmax7 * sigmax7);
Matrix actualCovarianceX7;
actualCovarianceX7 = bayesTree.marginalCovariance(ordering[X(7)]);
EXPECT(assert_equal(expectedCovarianceX7, actualCovarianceX7, tol));
EXPECT(assert_equal(expected7,actual7,tol));
}
/* ************************************************************************* */
TEST_UNSAFE( BayesTree, balanced_smoother_shortcuts )
{
// Create smoother with 7 nodes
Ordering ordering;
ordering += X(1),X(3),X(5),X(7),X(2),X(6),X(4);
GaussianFactorGraph smoother = createSmoother(7, ordering).first;
// Create the Bayes tree
BayesTree<GaussianConditional> bayesTree = *GaussianMultifrontalSolver(smoother).eliminate();
GaussianISAM isamTree(bayesTree);
// Check the conditional P(Root|Root)
GaussianBayesNet empty;
GaussianISAM::sharedClique R = isamTree.root();
GaussianBayesNet actual1 = GaussianISAM::shortcut(R,R);
EXPECT(assert_equal(empty,actual1,tol));
// Check the conditional P(C2|Root)
GaussianISAM::sharedClique C2 = isamTree[ordering[X(3)]];
GaussianBayesNet actual2 = GaussianISAM::shortcut(C2,R);
EXPECT(assert_equal(empty,actual2,tol));
// Check the conditional P(C3|Root), which should be equal to P(x2|x4)
/** TODO: Note for multifrontal conditional:
* p_x2_x4 is now an element conditional of the multifrontal conditional bayesTree[ordering[X(2)]]->conditional()
* We don't know yet how to take it out.
*/
// GaussianConditional::shared_ptr p_x2_x4 = bayesTree[ordering[X(2)]]->conditional();
// p_x2_x4->print("Conditional p_x2_x4: ");
// GaussianBayesNet expected3(p_x2_x4);
// GaussianISAM::sharedClique C3 = isamTree[ordering[X(1)]];
// GaussianBayesNet actual3 = GaussianISAM::shortcut(C3,R);
// EXPECT(assert_equal(expected3,actual3,tol));
}
///* ************************************************************************* */
//TEST( BayesTree, balanced_smoother_clique_marginals )
//{
// // Create smoother with 7 nodes
// Ordering ordering;
// ordering += X(1),X(3),X(5),X(7),X(2),X(6),X(4);
// GaussianFactorGraph smoother = createSmoother(7, ordering).first;
//
// // Create the Bayes tree
// GaussianBayesNet chordalBayesNet = *GaussianSequentialSolver(smoother).eliminate();
// GaussianISAM bayesTree(chordalBayesNet);
//
// // Check the clique marginal P(C3)
// double sigmax2_alt = 1/1.45533; // THIS NEEDS TO BE CHECKED!
// GaussianBayesNet expected = simpleGaussian(ordering[X(2)],zero(2),sigmax2_alt);
// push_front(expected,ordering[X(1)], zero(2), eye(2)*sqrt(2), ordering[X(2)], -eye(2)*sqrt(2)/2, ones(2));
// GaussianISAM::sharedClique R = bayesTree.root(), C3 = bayesTree[ordering[X(1)]];
// GaussianFactorGraph marginal = C3->marginal(R);
// GaussianVariableIndex varIndex(marginal);
// Permutation toFront(Permutation::PullToFront(C3->keys(), varIndex.size()));
// Permutation toFrontInverse(*toFront.inverse());
// varIndex.permute(toFront);
// BOOST_FOREACH(const GaussianFactor::shared_ptr& factor, marginal) {
// factor->permuteWithInverse(toFrontInverse); }
// GaussianBayesNet actual = *inference::EliminateUntil(marginal, C3->keys().size(), varIndex);
// actual.permuteWithInverse(toFront);
// EXPECT(assert_equal(expected,actual,tol));
//}
/* ************************************************************************* */
TEST_UNSAFE( BayesTree, balanced_smoother_joint )
{
// Create smoother with 7 nodes
Ordering ordering;
ordering += X(1),X(3),X(5),X(7),X(2),X(6),X(4);
GaussianFactorGraph smoother = createSmoother(7, ordering).first;
// Create the Bayes tree, expected to look like:
// x5 x6 x4
// x3 x2 : x4
// x1 : x2
// x7 : x6
BayesTree<GaussianConditional> chordalBayesNet = *GaussianMultifrontalSolver(smoother).eliminate();
GaussianISAM bayesTree(chordalBayesNet);
// Conditional density elements reused by both tests
const Vector sigma = ones(2);
const Matrix I = eye(2), A = -0.00429185*I;
// Check the joint density P(x1,x7) factored as P(x1|x7)P(x7)
GaussianBayesNet expected1;
// Why does the sign get flipped on the prior?
GaussianConditional::shared_ptr
parent1(new GaussianConditional(ordering[X(7)], zero(2), -1*I/sigmax7, ones(2)));
expected1.push_front(parent1);
push_front(expected1,ordering[X(1)], zero(2), I/sigmax7, ordering[X(7)], A/sigmax7, sigma);
GaussianBayesNet actual1 = *bayesTree.jointBayesNet(ordering[X(1)],ordering[X(7)]);
EXPECT(assert_equal(expected1,actual1,tol));
// // Check the joint density P(x7,x1) factored as P(x7|x1)P(x1)
// GaussianBayesNet expected2;
// GaussianConditional::shared_ptr
// parent2(new GaussianConditional(ordering[X(1)], zero(2), -1*I/sigmax1, ones(2)));
// expected2.push_front(parent2);
// push_front(expected2,ordering[X(7)], zero(2), I/sigmax1, ordering[X(1)], A/sigmax1, sigma);
// GaussianBayesNet actual2 = *bayesTree.jointBayesNet(ordering[X(7)],ordering[X(1)]);
// EXPECT(assert_equal(expected2,actual2,tol));
// Check the joint density P(x1,x4), i.e. with a root variable
GaussianBayesNet expected3;
GaussianConditional::shared_ptr
parent3(new GaussianConditional(ordering[X(4)], zero(2), I/sigmax4, ones(2)));
expected3.push_front(parent3);
double sig14 = 0.784465;
Matrix A14 = -0.0769231*I;
push_front(expected3,ordering[X(1)], zero(2), I/sig14, ordering[X(4)], A14/sig14, sigma);
GaussianBayesNet actual3 = *bayesTree.jointBayesNet(ordering[X(1)],ordering[X(4)]);
EXPECT(assert_equal(expected3,actual3,tol));
// // Check the joint density P(x4,x1), i.e. with a root variable, factored the other way
// GaussianBayesNet expected4;
// GaussianConditional::shared_ptr
// parent4(new GaussianConditional(ordering[X(1)], zero(2), -1.0*I/sigmax1, ones(2)));
// expected4.push_front(parent4);
// double sig41 = 0.668096;
// Matrix A41 = -0.055794*I;
// push_front(expected4,ordering[X(4)], zero(2), I/sig41, ordering[X(1)], A41/sig41, sigma);
// GaussianBayesNet actual4 = *bayesTree.jointBayesNet(ordering[X(4)],ordering[X(1)]);
// EXPECT(assert_equal(expected4,actual4,tol));
}
/* ************************************************************************* */
TEST_UNSAFE(BayesTree, simpleMarginal)
{
GaussianFactorGraph gfg;
Matrix A12 = Rot2::fromDegrees(45.0).matrix();
gfg.add(0, eye(2), zero(2), noiseModel::Isotropic::Sigma(2, 1.0));
gfg.add(0, -eye(2), 1, eye(2), ones(2), noiseModel::Isotropic::Sigma(2, 1.0));
gfg.add(1, -eye(2), 2, A12, ones(2), noiseModel::Isotropic::Sigma(2, 1.0));
Matrix expected(GaussianSequentialSolver(gfg).marginalCovariance(2));
Matrix actual(GaussianMultifrontalSolver(gfg).marginalCovariance(2));
EXPECT(assert_equal(expected, actual));
}
/* ************************************************************************* */
int main() { TestResult tr; return TestRegistry::runAllTests(tr);}
/* ************************************************************************* */