325 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			C++
		
	
	
			
		
		
	
	
			325 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			C++
		
	
	
| /* ----------------------------------------------------------------------------
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| 
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|  * GTSAM Copyright 2010, Georgia Tech Research Corporation,
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|  * Atlanta, Georgia 30332-0415
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|  * All Rights Reserved
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|  * Authors: Frank Dellaert, et al. (see THANKS for the full author list)
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| 
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|  * See LICENSE for the license information
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| 
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|  * -------------------------------------------------------------------------- */
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| 
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| /**
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|  * @file    testGaussianISAM.cpp
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|  * @brief   Unit tests for GaussianISAM
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|  * @author  Michael Kaess
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|  */
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| 
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| #include <tests/smallExample.h>
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| #include <gtsam/inference/Symbol.h>
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| #include <gtsam/linear/GaussianBayesTree.h>
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| #include <gtsam/linear/GaussianBayesNet.h>
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| #include <gtsam/linear/GaussianConditional.h>
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| #include <gtsam/linear/GaussianDensity.h>
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| #include <gtsam/linear/HessianFactor.h>
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| #include <gtsam/geometry/Rot2.h>
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| 
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| #include <CppUnitLite/TestHarness.h>
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| 
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| using namespace std;
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| using namespace gtsam;
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| using namespace example;
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| 
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| using symbol_shorthand::X;
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| using symbol_shorthand::L;
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| 
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| /* ************************************************************************* */
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| // Some numbers that should be consistent among all smoother tests
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| 
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| static double sigmax1 = 0.786153, /*sigmax2 = 1.0/1.47292,*/ sigmax3 = 0.671512, sigmax4 =
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|     0.669534 /*, sigmax5 = sigmax3, sigmax6 = sigmax2*/, sigmax7 = sigmax1;
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| 
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| static const double tol = 1e-4;
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| 
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| /* ************************************************************************* *
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|  Bayes tree for smoother with "natural" ordering:
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| C1 x6 x7
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| C2   x5 : x6
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| C3     x4 : x5
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| C4       x3 : x4
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| C5         x2 : x3
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| C6           x1 : x2
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| **************************************************************************** */
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| TEST( GaussianBayesTree, linear_smoother_shortcuts )
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| {
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|   // Create smoother with 7 nodes
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|   GaussianFactorGraph smoother = createSmoother(7);
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| 
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|   GaussianBayesTree bayesTree = *smoother.eliminateMultifrontal();
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| 
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|   // Create the Bayes tree
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|   LONGS_EQUAL(6, (long)bayesTree.size());
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| 
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|   // Check the conditional P(Root|Root)
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|   GaussianBayesNet empty;
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|   GaussianBayesTree::sharedClique R = bayesTree.roots().front();
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|   GaussianBayesNet actual1 = R->shortcut(R);
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|   EXPECT(assert_equal(empty,actual1,tol));
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| 
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|   // Check the conditional P(C2|Root)
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|   GaussianBayesTree::sharedClique C2 = bayesTree[X(5)];
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|   GaussianBayesNet actual2 = C2->shortcut(R);
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|   EXPECT(assert_equal(empty,actual2,tol));
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| 
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|   // Check the conditional P(C3|Root)
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|   double sigma3 = 0.61808;
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|   Matrix A56 = (Matrix(2,2) << -0.382022,0.,0.,-0.382022).finished();
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|   GaussianBayesNet expected3;
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|   expected3.emplace_shared<GaussianConditional>(X(5), Z_2x1, I_2x2/sigma3, X(6), A56/sigma3);
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|   GaussianBayesTree::sharedClique C3 = bayesTree[X(4)];
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|   GaussianBayesNet actual3 = C3->shortcut(R);
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|   EXPECT(assert_equal(expected3,actual3,tol));
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| 
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|   // Check the conditional P(C4|Root)
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|   double sigma4 = 0.661968;
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|   Matrix A46 = (Matrix(2,2) << -0.146067,0.,0.,-0.146067).finished();
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|   GaussianBayesNet expected4;
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|   expected4.emplace_shared<GaussianConditional>(X(4), Z_2x1, I_2x2/sigma4, X(6), A46/sigma4);
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|   GaussianBayesTree::sharedClique C4 = bayesTree[X(3)];
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|   GaussianBayesNet actual4 = C4->shortcut(R);
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|   EXPECT(assert_equal(expected4,actual4,tol));
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| }
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| 
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| /* ************************************************************************* *
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|  Bayes tree for smoother with "nested dissection" ordering:
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| 
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|    Node[x1] P(x1 | x2)
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|    Node[x3] P(x3 | x2 x4)
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|    Node[x5] P(x5 | x4 x6)
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|    Node[x7] P(x7 | x6)
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|    Node[x2] P(x2 | x4)
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|    Node[x6] P(x6 | x4)
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|    Node[x4] P(x4)
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| 
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|  becomes
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| 
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|    C1     x5 x6 x4
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|    C2      x3 x2 : x4
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|    C3        x1 : x2
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|    C4      x7 : x6
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| 
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| ************************************************************************* */
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| TEST(GaussianBayesTree, balanced_smoother_marginals) {
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|   // Create smoother with 7 nodes
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|   GaussianFactorGraph smoother = createSmoother(7);
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| 
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|   // Create the Bayes tree
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|   const Ordering ordering{X(1), X(3), X(5), X(7), X(2), X(6), X(4)};
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|   GaussianBayesTree bayesTree = *smoother.eliminateMultifrontal(ordering);
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| 
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|   VectorValues actualSolution = bayesTree.optimize();
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|   VectorValues expectedSolution = VectorValues::Zero(actualSolution);
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|   EXPECT(assert_equal(expectedSolution, actualSolution, tol));
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| 
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|   LONGS_EQUAL(4, bayesTree.size());
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| 
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|   double tol = 1e-5;
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| 
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|   // Check marginal on x1
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|   JacobianFactor actual1 = *bayesTree.marginalFactor(X(1));
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|   Matrix expectedCovX1 = I_2x2 * (sigmax1 * sigmax1);
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|   auto m = bayesTree.marginalFactor(X(1), EliminateCholesky);
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|   Matrix actualCovarianceX1 = m->information().inverse();
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|   EXPECT(assert_equal(expectedCovX1, actualCovarianceX1, tol));
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| 
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|   // Check marginal on x2
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|   double sigmax2 = 0.68712938;  // FIXME: this should be corrected analytically
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|   JacobianFactor actual2 = *bayesTree.marginalFactor(X(2));
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|   Matrix expectedCovX2 = I_2x2 * (sigmax2 * sigmax2);
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|   EXPECT(assert_equal(expectedCovX2, actual2.information().inverse(), tol));
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| 
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|   // Check marginal on x3
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|   JacobianFactor actual3 = *bayesTree.marginalFactor(X(3));
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|   Matrix expectedCovX3 = I_2x2 * (sigmax3 * sigmax3);
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|   EXPECT(assert_equal(expectedCovX3, actual3.information().inverse(), tol));
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| 
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|   // Check marginal on x4
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|   JacobianFactor actual4 = *bayesTree.marginalFactor(X(4));
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|   Matrix expectedCovX4 = I_2x2 * (sigmax4 * sigmax4);
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|   EXPECT(assert_equal(expectedCovX4, actual4.information().inverse(), tol));
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| 
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|   // Check marginal on x7 (should be equal to x1)
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|   JacobianFactor actual7 = *bayesTree.marginalFactor(X(7));
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|   Matrix expectedCovX7 = I_2x2 * (sigmax7 * sigmax7);
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|   EXPECT(assert_equal(expectedCovX7, actual7.information().inverse(), tol));
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| }
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| 
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| /* ************************************************************************* */
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| TEST( GaussianBayesTree, balanced_smoother_shortcuts )
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| {
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|   // Create smoother with 7 nodes
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|   GaussianFactorGraph smoother = createSmoother(7);
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| 
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|   // Create the Bayes tree
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|   const Ordering ordering{X(1), X(3), X(5), X(7), X(2), X(6), X(4)};
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|   GaussianBayesTree bayesTree = *smoother.eliminateMultifrontal(ordering);
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| 
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|   // Check the conditional P(Root|Root)
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|   GaussianBayesNet empty;
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|   GaussianBayesTree::sharedClique R = bayesTree.roots().front();
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|   GaussianBayesNet actual1 = R->shortcut(R);
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|   EXPECT(assert_equal(empty,actual1,tol));
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| 
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|   // Check the conditional P(C2|Root)
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|   GaussianBayesTree::sharedClique C2 = bayesTree[X(3)];
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|   GaussianBayesNet actual2 = C2->shortcut(R);
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|   EXPECT(assert_equal(empty,actual2,tol));
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| 
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|   // Check the conditional P(C3|Root), which should be equal to P(x2|x4)
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|   /** TODO: Note for multifrontal conditional:
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|    * p_x2_x4 is now an element conditional of the multifrontal conditional bayesTree[ordering[X(2)]]->conditional()
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|    * We don't know yet how to take it out.
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|    */
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| //  GaussianConditional::shared_ptr p_x2_x4 = bayesTree[ordering[X(2)]]->conditional();
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| //  p_x2_x4->print("Conditional p_x2_x4: ");
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| //  GaussianBayesNet expected3(p_x2_x4);
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| //  GaussianISAM::sharedClique C3 = isamTree[ordering[X(1)]];
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| //  GaussianBayesNet actual3 = GaussianISAM::shortcut(C3,R);
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| //  EXPECT(assert_equal(expected3,actual3,tol));
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| }
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| 
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| ///* ************************************************************************* */
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| //TEST( BayesTree, balanced_smoother_clique_marginals )
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| //{
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| //  // Create smoother with 7 nodes
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| //  const Ordering ordering{X(1),X(3),X(5),X(7),X(2),X(6),X(4)};
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| //  GaussianFactorGraph smoother = createSmoother(7, ordering).first;
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| //
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| //  // Create the Bayes tree
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| //  GaussianBayesNet chordalBayesNet = *GaussianSequentialSolver(smoother).eliminate();
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| //  GaussianISAM bayesTree(chordalBayesNet);
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| //
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| //  // Check the clique marginal P(C3)
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| //  double sigmax2_alt = 1/1.45533; // THIS NEEDS TO BE CHECKED!
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| //  GaussianBayesNet expected = simpleGaussian(ordering[X(2)],Z_2x1,sigmax2_alt);
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| //  push_front(expected,ordering[X(1)], Z_2x1, eye(2)*sqrt(2), ordering[X(2)], -eye(2)*sqrt(2)/2, ones(2));
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| //  GaussianISAM::sharedClique R = bayesTree.root(), C3 = bayesTree[ordering[X(1)]];
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| //  GaussianFactorGraph marginal = C3->marginal(R);
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| //  GaussianVariableIndex varIndex(marginal);
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| //  Permutation toFront(Permutation::PullToFront(C3->keys(), varIndex.size()));
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| //  Permutation toFrontInverse(*toFront.inverse());
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| //  varIndex.permute(toFront);
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| //  for(const GaussianFactor::shared_ptr& factor: marginal) {
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| //    factor->permuteWithInverse(toFrontInverse); }
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| //  GaussianBayesNet actual = *inference::EliminateUntil(marginal, C3->keys().size(), varIndex);
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| //  actual.permuteWithInverse(toFront);
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| //  EXPECT(assert_equal(expected,actual,tol));
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| //}
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| 
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| /* ************************************************************************* */
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| TEST( GaussianBayesTree, balanced_smoother_joint )
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| {
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|   // Create smoother with 7 nodes
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|   const Ordering ordering{X(1), X(3), X(5), X(7), X(2), X(6), X(4)};
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|   GaussianFactorGraph smoother = createSmoother(7);
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| 
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|   // Create the Bayes tree, expected to look like:
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|   //   x5 x6 x4
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|   //     x3 x2 : x4
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|   //       x1 : x2
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|   //     x7 : x6
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|   GaussianBayesTree bayesTree = *smoother.eliminateMultifrontal(ordering);
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| 
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|   // Conditional density elements reused by both tests
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|   const Matrix I = I_2x2, A = -0.00429185*I;
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| 
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|   // Check the joint density P(x1,x7) factored as P(x1|x7)P(x7)
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|   GaussianBayesNet expected1;
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|     // Why does the sign get flipped on the prior?
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|   expected1.emplace_shared<GaussianConditional>(X(1), Z_2x1, I/sigmax7, X(7), A/sigmax7);
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|   expected1.emplace_shared<GaussianConditional>(X(7), Z_2x1, -1*I/sigmax7);
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|   GaussianBayesNet actual1 = *bayesTree.jointBayesNet(X(1),X(7));
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|   EXPECT(assert_equal(expected1, actual1, tol));
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| 
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|   //  // Check the joint density P(x7,x1) factored as P(x7|x1)P(x1)
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|   //  GaussianBayesNet expected2;
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|   //  GaussianConditional::shared_ptr
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|   //      parent2(new GaussianConditional(X(1), Z_2x1, -1*I/sigmax1, ones(2)));
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|   //    expected2.push_front(parent2);
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|   //  push_front(expected2,X(7), Z_2x1, I/sigmax1, X(1), A/sigmax1, sigma);
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|   //  GaussianBayesNet actual2 = *bayesTree.jointBayesNet(X(7),X(1));
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|   //  EXPECT(assert_equal(expected2,actual2,tol));
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| 
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|   // Check the joint density P(x1,x4), i.e. with a root variable
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|   double sig14 = 0.784465;
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|   Matrix A14 = -0.0769231*I;
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|   GaussianBayesNet expected3;
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|   expected3.emplace_shared<GaussianConditional>(X(1), Z_2x1, I/sig14, X(4), A14/sig14);
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|   expected3.emplace_shared<GaussianConditional>(X(4), Z_2x1, I/sigmax4);
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|   GaussianBayesNet actual3 = *bayesTree.jointBayesNet(X(1),X(4));
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|   EXPECT(assert_equal(expected3,actual3,tol));
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| 
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|   //  // Check the joint density P(x4,x1), i.e. with a root variable, factored the other way
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|   //  GaussianBayesNet expected4;
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|   //  GaussianConditional::shared_ptr
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|   //      parent4(new GaussianConditional(X(1), Z_2x1, -1.0*I/sigmax1, ones(2)));
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|   //    expected4.push_front(parent4);
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|   //  double sig41 = 0.668096;
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|   //  Matrix A41 = -0.055794*I;
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|   //  push_front(expected4,X(4), Z_2x1, I/sig41, X(1), A41/sig41, sigma);
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|   //  GaussianBayesNet actual4 = *bayesTree.jointBayesNet(X(4),X(1));
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|   //  EXPECT(assert_equal(expected4,actual4,tol));
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| }
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| 
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| /* ************************************************************************* */
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| TEST(GaussianBayesTree, shortcut_overlapping_separator)
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| {
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|   // Test computing shortcuts when the separator overlaps.  This previously
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|   // would have highlighted a problem where information was duplicated.
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| 
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|   // Create factor graph:
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|   // f(1,2,5)
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|   // f(3,4,5)
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|   // f(5,6)
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|   // f(6,7)
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|   GaussianFactorGraph fg;
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|   noiseModel::Diagonal::shared_ptr model = noiseModel::Unit::Create(1);
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|   fg.add(1, (Matrix(1, 1) <<  1.0).finished(), 3, (Matrix(1, 1) <<  2.0).finished(), 5, (Matrix(1, 1) <<  3.0).finished(), (Vector(1) << 4.0).finished(), model);
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|   fg.add(1, (Matrix(1, 1) <<  5.0).finished(), (Vector(1) << 6.0).finished(), model);
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|   fg.add(2, (Matrix(1, 1) <<  7.0).finished(), 4, (Matrix(1, 1) <<  8.0).finished(), 5, (Matrix(1, 1) <<  9.0).finished(), (Vector(1) << 10.0).finished(), model);
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|   fg.add(2, (Matrix(1, 1) <<  11.0).finished(), (Vector(1) << 12.0).finished(), model);
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|   fg.add(5, (Matrix(1, 1) <<  13.0).finished(), 6, (Matrix(1, 1) <<  14.0).finished(), (Vector(1) << 15.0).finished(), model);
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|   fg.add(6, (Matrix(1, 1) <<  17.0).finished(), 7, (Matrix(1, 1) <<  18.0).finished(), (Vector(1) << 19.0).finished(), model);
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|   fg.add(7, (Matrix(1, 1) <<  20.0).finished(), (Vector(1) << 21.0).finished(), model);
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| 
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|   // Eliminate into BayesTree
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|   // c(6,7)
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|   // c(5|6)
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|   //   c(1,2|5)
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|   //   c(3,4|5)
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|   Ordering ordering(fg.keys());
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|   GaussianBayesTree bt = *fg.eliminateMultifrontal(ordering); // eliminate in increasing key order, fg.keys() is sorted.
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| 
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|   GaussianFactorGraph joint = *bt.joint(1,2, EliminateQR);
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| 
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|   Matrix expectedJointJ = (Matrix(2,3) <<
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|     5, 0, 6,
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|     0, -11, -12
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|     ).finished();
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| 
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|   Matrix actualJointJ = joint.augmentedJacobian();
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| 
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|   // PR 315: sign of rows in joint are immaterial
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|   if (signbit(expectedJointJ(0, 2)) != signbit(actualJointJ(0, 2)))
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|     expectedJointJ.row(0) = -expectedJointJ.row(0);
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| 
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|   if (signbit(expectedJointJ(1, 2)) != signbit(actualJointJ(1, 2)))
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|     expectedJointJ.row(1) = -expectedJointJ.row(1);
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| 
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|   EXPECT(assert_equal(expectedJointJ, actualJointJ));
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| }
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| 
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| /* ************************************************************************* */
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| int main() { TestResult tr; return TestRegistry::runAllTests(tr);}
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| /* ************************************************************************* */
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