gtsam/gtsam_unstable/linear/tests/testLPSolver.cpp

239 lines
8.3 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 testQPSolver.cpp
* @brief Test simple QP solver for a linear inequality constraint
* @date Apr 10, 2014
* @author Duy-Nguyen Ta
*/
#include <gtsam_unstable/linear/LPInitSolver.h>
#include <gtsam_unstable/linear/LPSolver.h>
#include <gtsam/base/Testable.h>
#include <gtsam/inference/FactorGraph-inst.h>
#include <gtsam/inference/Symbol.h>
#include <gtsam/linear/GaussianFactorGraph.h>
#include <gtsam/linear/VectorValues.h>
#include <gtsam_unstable/linear/EqualityFactorGraph.h>
#include <gtsam_unstable/linear/InequalityFactorGraph.h>
#include <gtsam_unstable/linear/InfeasibleInitialValues.h>
#include <CppUnitLite/TestHarness.h>
using namespace std;
using namespace gtsam;
using namespace gtsam::symbol_shorthand;
static const Vector kOne = Vector::Ones(1), kZero = Vector::Zero(1);
/* ************************************************************************* */
/**
* min -x1-x2
* s.t. x1 + 2x2 <= 4
* 4x1 + 2x2 <= 12
* -x1 + x2 <= 1
* x1, x2 >= 0
*/
LP simpleLP1() {
LP lp;
lp.cost = LinearCost(1, Vector2(-1., -1.)); // min -x1-x2 (max x1+x2)
lp.inequalities.add(1, Vector2(-1, 0), 0, 1); // x1 >= 0
lp.inequalities.add(1, Vector2(0, -1), 0, 2); // x2 >= 0
lp.inequalities.add(1, Vector2(1, 2), 4, 3); // x1 + 2*x2 <= 4
lp.inequalities.add(1, Vector2(4, 2), 12, 4); // 4x1 + 2x2 <= 12
lp.inequalities.add(1, Vector2(-1, 1), 1, 5); // -x1 + x2 <= 1
return lp;
}
/* ************************************************************************* */
namespace gtsam {
TEST(LPInitSolver, InfiniteLoopSingleVar) {
LP lp;
lp.cost = LinearCost(1, Vector3(0, 0, 1)); // min alpha
lp.inequalities.add(1, Vector3(-2, -1, -1), -2, 1); //-2x-y-a <= -2
lp.inequalities.add(1, Vector3(-1, 2, -1), 6, 2); // -x+2y-a <= 6
lp.inequalities.add(1, Vector3(-1, 0, -1), 0, 3); // -x - a <= 0
lp.inequalities.add(1, Vector3(1, 0, -1), 20, 4); // x - a <= 20
lp.inequalities.add(1, Vector3(0, -1, -1), 0, 5); // -y - a <= 0
LPSolver solver(lp);
VectorValues starter;
starter.insert(1, Vector3(0, 0, 2));
VectorValues results, duals;
std::tie(results, duals) = solver.optimize(starter);
VectorValues expected;
expected.insert(1, Vector3(13.5, 6.5, -6.5));
CHECK(assert_equal(results, expected, 1e-7));
}
TEST(LPInitSolver, InfiniteLoopMultiVar) {
LP lp;
Key X = symbol('X', 1);
Key Y = symbol('Y', 1);
Key Z = symbol('Z', 1);
lp.cost = LinearCost(Z, kOne); // min alpha
lp.inequalities.add(X, -2.0 * kOne, Y, -1.0 * kOne, Z, -1.0 * kOne, -2,
1); //-2x-y-alpha <= -2
lp.inequalities.add(X, -1.0 * kOne, Y, 2.0 * kOne, Z, -1.0 * kOne, 6,
2); // -x+2y-alpha <= 6
lp.inequalities.add(X, -1.0 * kOne, Z, -1.0 * kOne, 0,
3); // -x - alpha <= 0
lp.inequalities.add(X, 1.0 * kOne, Z, -1.0 * kOne, 20,
4); // x - alpha <= 20
lp.inequalities.add(Y, -1.0 * kOne, Z, -1.0 * kOne, 0,
5); // -y - alpha <= 0
LPSolver solver(lp);
VectorValues starter;
starter.insert(X, kZero);
starter.insert(Y, kZero);
starter.insert(Z, Vector::Constant(1, 2.0));
VectorValues results, duals;
std::tie(results, duals) = solver.optimize(starter);
VectorValues expected;
expected.insert(X, Vector::Constant(1, 13.5));
expected.insert(Y, Vector::Constant(1, 6.5));
expected.insert(Z, Vector::Constant(1, -6.5));
CHECK(assert_equal(results, expected, 1e-7));
}
TEST(LPInitSolver, Initialization) {
LP lp = simpleLP1();
LPInitSolver initSolver(lp);
GaussianFactorGraph::shared_ptr initOfInitGraph =
initSolver.buildInitOfInitGraph();
VectorValues x0 = initOfInitGraph->optimize();
VectorValues expected_x0;
expected_x0.insert(1, Vector::Zero(2));
CHECK(assert_equal(expected_x0, x0, 1e-10));
double y0 = initSolver.compute_y0(x0);
double expected_y0 = 0.0;
DOUBLES_EQUAL(expected_y0, y0, 1e-7);
Key yKey = 2;
LP::shared_ptr initLP = initSolver.buildInitialLP(yKey);
LP expectedInitLP;
expectedInitLP.cost = LinearCost(yKey, kOne);
expectedInitLP.inequalities.add(1, Vector2(-1, 0), 2, Vector::Constant(1, -1),
0, 1); // -x1 - y <= 0
expectedInitLP.inequalities.add(1, Vector2(0, -1), 2, Vector::Constant(1, -1),
0, 2); // -x2 - y <= 0
expectedInitLP.inequalities.add(1, Vector2(1, 2), 2, Vector::Constant(1, -1),
4,
3); // x1 + 2*x2 - y <= 4
expectedInitLP.inequalities.add(1, Vector2(4, 2), 2, Vector::Constant(1, -1),
12,
4); // 4x1 + 2x2 - y <= 12
expectedInitLP.inequalities.add(1, Vector2(-1, 1), 2, Vector::Constant(1, -1),
1,
5); // -x1 + x2 - y <= 1
CHECK(assert_equal(expectedInitLP, *initLP, 1e-10));
LPSolver lpSolveInit(*initLP);
VectorValues xy0(x0);
xy0.insert(yKey, Vector::Constant(1, y0));
VectorValues xyInit = lpSolveInit.optimize(xy0).first;
VectorValues expected_init;
expected_init.insert(1, Vector::Ones(2));
expected_init.insert(2, Vector::Constant(1, -1));
CHECK(assert_equal(expected_init, xyInit, 1e-10));
VectorValues x = initSolver.solve();
CHECK(lp.isFeasible(x));
}
} // namespace gtsam
/* ************************************************************************* */
/**
* TEST gtsam solver with an over-constrained system
* x + y = 1
* x - y = 5
* x + 2y = 6
*/
TEST(LPSolver, OverConstrainedLinearSystem) {
GaussianFactorGraph graph;
Matrix A1 = Vector3(1, 1, 1);
Matrix A2 = Vector3(1, -1, 2);
Vector b = Vector3(1, 5, 6);
graph.add(1, A1, 2, A2, b, noiseModel::Constrained::All(3));
VectorValues x = graph.optimize();
// This check confirms that gtsam linear constraint solver can't handle
// over-constrained system
CHECK(graph[0]->error(x) != 0.0);
}
TEST(LPSolver, overConstrainedLinearSystem2) {
GaussianFactorGraph graph;
graph.add(1, I_1x1, 2, I_1x1, kOne, noiseModel::Constrained::All(1));
graph.add(1, I_1x1, 2, -I_1x1, 5 * kOne, noiseModel::Constrained::All(1));
graph.add(1, I_1x1, 2, 2 * I_1x1, 6 * kOne, noiseModel::Constrained::All(1));
VectorValues x = graph.optimize();
// This check confirms that gtsam linear constraint solver can't handle
// over-constrained system
CHECK(graph.error(x) != 0.0);
}
/* ************************************************************************* */
TEST(LPSolver, SimpleTest1) {
LP lp = simpleLP1();
LPSolver lpSolver(lp);
VectorValues init;
init.insert(1, Vector::Zero(2));
VectorValues x1 =
lpSolver.buildWorkingGraph(InequalityFactorGraph(), init).optimize();
VectorValues expected_x1;
expected_x1.insert(1, Vector::Ones(2));
CHECK(assert_equal(expected_x1, x1, 1e-10));
VectorValues result, duals;
std::tie(result, duals) = lpSolver.optimize(init);
VectorValues expectedResult;
expectedResult.insert(1, Vector2(8. / 3., 2. / 3.));
CHECK(assert_equal(expectedResult, result, 1e-10));
}
/* ************************************************************************* */
TEST(LPSolver, TestWithoutInitialValues) {
LP lp = simpleLP1();
LPSolver lpSolver(lp);
VectorValues result, duals, expectedResult;
expectedResult.insert(1, Vector2(8. / 3., 2. / 3.));
std::tie(result, duals) = lpSolver.optimize();
CHECK(assert_equal(expectedResult, result));
}
/**
* TODO: More TEST cases:
* - Infeasible
* - Unbounded
* - Underdetermined
*/
/* ************************************************************************* */
TEST(LPSolver, LinearCost) {
LinearCost cost(1, Vector3(2., 4., 6.));
VectorValues x;
x.insert(1, Vector3(1., 3., 5.));
double error = cost.error(x);
double expectedError = 44.0;
DOUBLES_EQUAL(expectedError, error, 1e-100);
}
/* ************************************************************************* */
int main() {
TestResult tr;
return TestRegistry::runAllTests(tr);
}
/* ************************************************************************* */