gtsam/gtsam_unstable/linear/tests/testConditioning.cpp

251 lines
11 KiB
C++

/**
* @file testConditioning.cpp
*
* @brief Experiments using backsubstitution for conditioning (not summarization, it turns out)
*
* @date Sep 3, 2012
* @author Alex Cunningham
*/
#include <CppUnitLite/TestHarness.h>
#include <gtsam/base/TestableAssertions.h>
#include <boost/assign/std/set.hpp>
#include <gtsam_unstable/linear/conditioning.h>
using namespace std;
using namespace boost::assign;
using namespace gtsam;
const double tol = 1e-5;
// Simple example
Matrix R = Matrix_(3,3,
1.0,-2.0,-3.0,
0.0, 3.0,-5.0,
0.0, 0.0, 6.0);
Vector d = Vector_(3,
0.1, 0.2, 0.3);
Vector x = Vector_(3,
0.55,
0.15,
0.05);
/* ************************************************************************* */
TEST( testConditioning, directed_elimination_example ) {
// create a 3-variable system from which to eliminate variables
// Scalar variables, pre-factorized into R,d system
// Use multifrontal representation
// Variables 0, 1, 2 - want to summarize out 1
Vector expx = R.triangularView<Eigen::Upper>().solve(d);
EXPECT(assert_equal(x, expx, tol));
EXPECT(assert_equal(Vector(R*x), d, tol));
// backsub-summarized version
Matrix Rprime = Matrix_(2,2,
1.0,-3.0,
0.0, 6.0);
Vector dprime = Vector_(2,
d(0) - R(0,1)*x(1),
d(2));
Vector xprime = Vector_(2,
x(0), // Same solution, just smaller
x(2));
EXPECT(assert_equal(Vector(Rprime*xprime), dprime, tol));
}
/* ************************************************************************* */
TEST( testConditioning, directed_elimination_singlefrontal ) {
// Gaussian conditional with a single frontal variable, parent is to be removed
// Top row from above example
Index root_key = 0, removed_key = 1, remaining_parent = 2;
Matrix R11 = Matrix_(1,1, 1.0), R22 = Matrix_(1,1, 3.0), S = Matrix_(1,1,-2.0), T = Matrix_(1,1,-3.0);
Vector d0 = d.segment(0,1), d1 = d.segment(1,1), sigmas = Vector_(1, 1.0);
GaussianConditional::shared_ptr initConditional(new
GaussianConditional(root_key, d0, R11, removed_key, S, remaining_parent, T, sigmas));
VectorValues solution;
solution.insert(0, x.segment(0,1));
solution.insert(1, x.segment(1,1));
solution.insert(2, x.segment(2,1));
std::set<Index> saved_indices;
saved_indices += root_key, remaining_parent;
GaussianConditional::shared_ptr actSummarized = conditionDensity(initConditional, saved_indices, solution);
GaussianConditional::shared_ptr expSummarized(new
GaussianConditional(root_key, d0 - S*x(1), R11, remaining_parent, T, sigmas));
CHECK(actSummarized);
EXPECT(assert_equal(*expSummarized, *actSummarized, tol));
// Simple test of base case: if target index isn't present, return clone
GaussianConditional::shared_ptr actSummarizedSimple = conditionDensity(expSummarized, saved_indices, solution);
CHECK(actSummarizedSimple);
EXPECT(assert_equal(*expSummarized, *actSummarizedSimple, tol));
// case where frontal variable is to be eliminated - return null
GaussianConditional::shared_ptr removeFrontalInit(new
GaussianConditional(removed_key, d1, R22, remaining_parent, T, sigmas));
GaussianConditional::shared_ptr actRemoveFrontal = conditionDensity(removeFrontalInit, saved_indices, solution);
EXPECT(!actRemoveFrontal);
}
/* ************************************************************************* */
TEST( testConditioning, directed_elimination_multifrontal ) {
// Use top two rows from the previous example
Index root_key = 0, removed_key = 1, remaining_parent = 2;
Matrix R11 = R.topLeftCorner(2,2), S = R.block(0,2,2,1),
Sprime = Matrix_(1,1,-2.0), R11prime = Matrix_(1,1, 1.0);
Vector d1 = d.segment(0,2), sigmas1 = Vector_(1, 1.0), sigmas2 = Vector_(2, 1.0, 1.0);
std::list<std::pair<Index, Matrix> > terms;
terms += make_pair(root_key, Matrix(R11.col(0)));
terms += make_pair(removed_key, Matrix(R11.col(1)));
terms += make_pair(remaining_parent, S);
GaussianConditional::shared_ptr initConditional(new GaussianConditional(terms, 2, d1, sigmas2));
VectorValues solution;
solution.insert(0, x.segment(0,1));
solution.insert(1, x.segment(1,1));
solution.insert(2, x.segment(2,1));
std::set<Index> saved_indices;
saved_indices += root_key, remaining_parent;
GaussianConditional::shared_ptr actSummarized = conditionDensity(initConditional, saved_indices, solution);
GaussianConditional::shared_ptr expSummarized(new
GaussianConditional(root_key, d.segment(0,1) - Sprime*x(1), R11prime, remaining_parent, R.block(0,2,1,1), sigmas1));
CHECK(actSummarized);
EXPECT(assert_equal(*expSummarized, *actSummarized, tol));
}
/* ************************************************************************* */
TEST( testConditioning, directed_elimination_multifrontal_multidim ) {
// use larger example, three frontal variables, dim = 2 each, two parents (one removed)
// Vars: 0, 1, 2, 3, 4; frontal: 0, 1, 2. parents: 3, 4;
// Remove 1, 3
Matrix Rinit = Matrix_(6, 11,
1.0, 0.0, 2.0, 0.0, 3.0, 0.0, 1.0, 0.0, -1.0, 0.0, 0.1,
0.0, 1.0, 0.0, 2.0, 0.0, 3.0, 0.0, 1.0, 0.0, 1.0, 0.2,
0.0, 0.0, 3.0, 0.0, 4.0, 0.0, 0.0,-1.0, 1.0, 0.0, 0.3,
0.0, 0.0, 0.0, 4.0, 0.0, 4.0, 3.0, 2.0, 0.0, 9.0, 0.4,
0.0, 0.0, 0.0, 0.0, 5.0, 0.0, 7.0, 0.0, 3.0, 0.0, 0.5,
0.0, 0.0, 0.0, 0.0, 0.0, 4.0, 0.0, 8.0, 0.0, 6.0, 0.6);
vector<size_t> init_dims; init_dims += 2, 2, 2, 2, 2, 1;
GaussianConditional::rsd_type init_matrices(Rinit, init_dims.begin(), init_dims.end());
Vector sigmas = ones(6);
vector<size_t> init_keys; init_keys += 0, 1, 2, 3, 4;
GaussianConditional::shared_ptr initConditional(new
GaussianConditional(init_keys.begin(), init_keys.end(), 3, init_matrices, sigmas));
// Construct a solution vector
VectorValues solution;
solution.insert(0, zero(2));
solution.insert(1, zero(2));
solution.insert(2, zero(2));
solution.insert(3, Vector_(2, 1.0, 2.0));
solution.insert(4, Vector_(2, 3.0, 4.0));
initConditional->solveInPlace(solution);
std::set<Index> saved_indices;
saved_indices += 0, 2, 4;
GaussianConditional::shared_ptr actSummarized = conditionDensity(initConditional, saved_indices, solution);
CHECK(actSummarized);
Matrix Rexp = Matrix_(4, 7,
1.0, 0.0, 3.0, 0.0, -1.0, 0.0, 0.1,
0.0, 1.0, 0.0, 3.0, 0.0, 1.0, 0.2,
0.0, 0.0, 5.0, 0.0, 3.0, 0.0, 0.5,
0.0, 0.0, 0.0, 4.0, 0.0, 6.0, 0.6);
// Update rhs
Rexp.block(0, 6, 2, 1) -= Rinit.block(0, 2, 2, 2) * solution.at(1) + Rinit.block(0, 6, 2, 2) * solution.at(3);
Rexp.block(2, 6, 2, 1) -= Rinit.block(4, 6, 2, 2) * solution.at(3);
vector<size_t> exp_dims; exp_dims += 2, 2, 2, 1;
GaussianConditional::rsd_type exp_matrices(Rexp, exp_dims.begin(), exp_dims.end());
Vector exp_sigmas = ones(4);
vector<size_t> exp_keys; exp_keys += 0, 2, 4;
GaussianConditional expSummarized(exp_keys.begin(), exp_keys.end(), 2, exp_matrices, exp_sigmas);
EXPECT(assert_equal(expSummarized, *actSummarized, tol));
}
/* ************************************************************************* */
TEST( testConditioning, directed_elimination_multifrontal_multidim2 ) {
// Example from LinearAugmentedSystem
// 4 variables, last two in ordering kept - should be able to do this with no computation.
vector<size_t> init_dims; init_dims += 3, 3, 2, 2, 1;
//Full initial conditional: density on [3] [4] [5] [6]
Matrix Rinit = Matrix_(10, 11,
8.78422312, -0.0375455118, -0.0387376278, -5.059576, 0.0, 0.0, -0.0887200041, 0.00429643583, -0.130078263, 0.0193260727, 0.0,
0.0, 8.46951839, 9.51456887, -0.0224291821, -5.24757636, 0.0, 0.0586258904, -0.173455825, 0.11090295, -0.330696013, 0.0,
0.0, 0.0, 16.5539485, 0.00105159359, -2.35354497, -6.04085484, -0.0212095105, 0.0978729072, 0.00471054272, 0.0694956367, 0.0,
0.0, 0.0, 0.0, 10.9015885, -0.0105694572, 0.000582715469, -0.0410535006, 0.00162772139, -0.0601433772, 0.0082824087,0.0,
0.0, 0.0, 0.0, 0.0, 10.5531086, -1.34722553, 0.02438072, -0.0644224578, 0.0561372492, -0.148932792, 0.0,
0.0, 0.0, 0.0, 0.0, 0.0, 21.4870439, -0.00443305851, 0.0234766354, 0.00484572411, 0.0101997356, 0.0,
0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 2.73892865, 0.0242046766, -0.0459727048, 0.0445071938, 0.0,
0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 2.61246954, 0.02287419, -0.102870789, 0.0,
0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 2.04823446, -0.302033014, 0.0,
0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 2.24068986, 0.0);
Vector dinit = Vector_(10,
-0.00186915, 0.00318554, 0.000592421, -0.000861, 0.00171528, 0.000274123, -0.0284011, 0.0275465, 0.0439795, -0.0222134);
Rinit.rightCols(1) = dinit;
Vector sigmas = ones(10);
GaussianConditional::rsd_type init_matrices(Rinit, init_dims.begin(), init_dims.end());
vector<size_t> init_keys; init_keys += 3, 4, 5, 6;
GaussianConditional::shared_ptr initConditional(new
GaussianConditional(init_keys.begin(), init_keys.end(), 4, init_matrices, sigmas));
// Calculate a solution
VectorValues solution;
solution.insert(0, zero(3));
solution.insert(1, zero(3));
solution.insert(2, zero(3));
solution.insert(3, zero(3));
solution.insert(4, zero(3));
solution.insert(5, zero(2));
solution.insert(6, zero(2));
initConditional->solveInPlace(solution);
// Perform summarization
std::set<Index> saved_indices;
saved_indices += 5, 6;
GaussianConditional::shared_ptr actSummarized = conditionDensity(initConditional, saved_indices, solution);
CHECK(actSummarized);
// Create expected value on [5], [6]
Matrix Rexp = Matrix_(4, 5,
2.73892865, 0.0242046766, -0.0459727048, 0.0445071938, -0.0284011,
0.0, 2.61246954, 0.02287419, -0.102870789, 0.0275465,
0.0, 0.0, 2.04823446, -0.302033014, 0.0439795,
0.0, 0.0, 0.0, 2.24068986, -0.0222134);
Vector expsigmas = ones(4);
vector<size_t> exp_dims; exp_dims += 2, 2, 1;
GaussianConditional::rsd_type exp_matrices(Rexp, exp_dims.begin(), exp_dims.end());
vector<size_t> exp_keys; exp_keys += 5, 6;
GaussianConditional expConditional(exp_keys.begin(), exp_keys.end(), 2, exp_matrices, expsigmas);
EXPECT(assert_equal(expConditional, *actSummarized, tol));
}
/* ************************************************************************* */
int main() { TestResult tr; return TestRegistry::runAllTests(tr); }
/* ************************************************************************* */