gtsam/cpp/testBayesNetPreconditioner.cpp

133 lines
4.2 KiB
C++

/**
* @file testBayesNetConditioner.cpp
* @brief Unit tests for BayesNetConditioner
* @author Frank Dellaert
**/
#include <boost/foreach.hpp>
#include <boost/tuple/tuple.hpp>
#include <CppUnitLite/TestHarness.h>
#define GTSAM_MAGIC_KEY
#include "Ordering.h"
#include "smallExample.h"
#include "BayesNetPreconditioner.h"
#include "iterative-inl.h"
using namespace std;
using namespace gtsam;
using namespace example;
/* ************************************************************************* */
TEST( BayesNetPreconditioner, operators )
{
// Build a simple Bayes net
// small Bayes Net x <- y, x=2D, y=1D
// 1 2 3 x1 0
// 0 1 2 * x2 = 0
// 0 0 1 x3 1
// Create a scalar Gaussian on y
GaussianBayesNet bn = scalarGaussian("y", 1, 0.1);
// Add a conditional node with one parent |Rx+Sy-d|
Matrix R11 = Matrix_(2, 2, 1.0, 2.0, 0.0, 1.0), S12 = Matrix_(2, 1, 3.0, 2.0);
Vector d = zero(2);
Vector sigmas = Vector_(2, 0.1, 0.1);
push_front(bn, "x", d, R11, "y", S12, sigmas);
// Create Precondioner class
GaussianFactorGraph dummy;
BayesNetPreconditioner P(dummy,bn);
// inv(R1)*d should equal solution [1;-2;1]
VectorConfig D;
D.insert("x", d);
D.insert("y", Vector_(1, 1.0 / 0.1)); // corrected by sigma
VectorConfig expected1;
expected1.insert("x", Vector_(2, 1.0, -2.0));
expected1.insert("y", Vector_(1, 1.0));
VectorConfig actual1 = P.backSubstitute(D);
CHECK(assert_equal(expected1,actual1));
// inv(R1')*ones should equal ?
VectorConfig ones;
ones.insert("x", Vector_(2, 1.0, 1.0));
ones.insert("y", Vector_(1, 1.0));
VectorConfig expected2;
expected2.insert("x", Vector_(2, 0.1, -0.1));
expected2.insert("y", Vector_(1, 0.0));
VectorConfig actual2 = P.backSubstituteTranspose(ones);
CHECK(assert_equal(expected2,actual2));
}
/* ************************************************************************* */
TEST( BayesNetPreconditioner, conjugateGradients )
{
// Build a planar graph
GaussianFactorGraph Ab;
VectorConfig xtrue;
size_t N = 3;
boost::tie(Ab, xtrue) = planarGraph(N); // A*x-b
// Get the spanning tree and corresponding ordering
GaussianFactorGraph Ab1, Ab2; // A1*x-b1 and A2*x-b2
boost::tie(Ab1, Ab2) = splitOffPlanarTree(N, Ab);
// Eliminate the spanning tree to build a prior
Ordering ordering = planarOrdering(N);
GaussianBayesNet Rc1 = Ab1.eliminate(ordering); // R1*x-c1
VectorConfig xbar = optimize(Rc1); // xbar = inv(R1)*c1
// Create BayesNet-preconditioned system
BayesNetPreconditioner system(Ab,Rc1);
// Create zero config y0 and perturbed config y1
VectorConfig y0;
Vector z2 = zero(2);
BOOST_FOREACH(const Symbol& j, ordering) y0.insert(j,z2);
VectorConfig y1 = y0;
y1["x2003"] = Vector_(2, 1.0, -1.0);
VectorConfig x1 = system.x(y1);
// Check gradient for y0
VectorConfig expectedGradient0;
expectedGradient0.insert("x1001", Vector_(2,-1000.,-1000.));
expectedGradient0.insert("x1002", Vector_(2, 0., -300.));
expectedGradient0.insert("x1003", Vector_(2, 0., -300.));
expectedGradient0.insert("x2001", Vector_(2, -100., 200.));
expectedGradient0.insert("x2002", Vector_(2, -100., 0.));
expectedGradient0.insert("x2003", Vector_(2, -100., -200.));
expectedGradient0.insert("x3001", Vector_(2, -100., 100.));
expectedGradient0.insert("x3002", Vector_(2, -100., 0.));
expectedGradient0.insert("x3003", Vector_(2, -100., -100.));
VectorConfig actualGradient0 = system.gradient(y0);
CHECK(assert_equal(expectedGradient0,actualGradient0));
#ifdef VECTORBTREE
CHECK(actualGradient0.cloned(y0));
#endif
// Solve using PCG
bool verbose = false;
double epsilon = 1e-6; // had to crank this down !!!
size_t maxIterations = 100;
VectorConfig actual_y = gtsam::conjugateGradients<BayesNetPreconditioner,
VectorConfig, Errors>(system, y1, verbose, epsilon, epsilon, maxIterations);
VectorConfig actual_x = system.x(actual_y);
CHECK(assert_equal(xtrue,actual_x));
// Compare with non preconditioned version:
VectorConfig actual2 = conjugateGradientDescent(Ab, x1, verbose, epsilon,
maxIterations);
CHECK(assert_equal(xtrue,actual2));
}
/* ************************************************************************* */
int main() {
TestResult tr;
return TestRegistry::runAllTests(tr);
}
/* ************************************************************************* */