gtsam/gtsam_unstable/nonlinear/tests/testLinearlyConstrainedNonl...

138 lines
4.7 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 testLinearlyConstrainedNonlinearOptimizer.cpp
* @brief Unit tests for LinearlyConstrainedNonlinearOptimizer
* @author Krunal Chande
* @author Duy-Nguyen Ta
* @author Luca Carlone
* @date Dec 15, 2014
*/
#include <gtsam/nonlinear/NonlinearFactorGraph.h>
#include <gtsam/nonlinear/LinearContainerFactor.h>
#include <gtsam/inference/Symbol.h>
#include <gtsam_unstable/linear/QPSolver.h>
#include <CppUnitLite/TestHarness.h>
#include <iostream>
namespace gtsam {
struct LinearlyConstrainedNLP {
NonlinearFactorGraph cost;
LinearEqualityFactorGraph equalities;
LinearInequalityFactorGraph inequalities;
};
struct LinearlyConstrainedNLPState {
Values values;
VectorValues duals;
bool converged;
LinearlyConstrainedNLPState(const Values& initialValues) :
values(initialValues), duals(VectorValues()), converged(false) {
}
};
class LinearlyConstrainedNonLinearOptimizer {
LinearlyConstrainedNLP lcNLP_;
public:
LinearlyConstrainedNonLinearOptimizer(const LinearlyConstrainedNLP& lcNLP): lcNLP_(lcNLP) {}
LinearlyConstrainedNLPState iterate(const LinearlyConstrainedNLPState& state) const {
QP qp;
qp.cost = lcNLP_.cost.linearize(state.values);
qp.equalities = lcNLP_.equalities;
qp.inequalities = lcNLP_.inequalities;
QPSolver qpSolver(qp);
VectorValues delta, duals;
boost::tie(delta, duals) = qpSolver.optimize();
LinearlyConstrainedNLPState newState;
newState.values = state.values.retract(delta);
newState.duals = duals;
newState.converged = checkConvergence(newState.values, newState.duals);
return newState;
}
/**
* Main optimization function.
*/
std::pair<Values, VectorValues> optimize(const Values& initialValues) const {
LinearlyConstrainedNLPState state(initialValues);
while(!state.converged){
state = iterate(state);
}
return std::make_pair(initialValues, VectorValues());
}
};
}
using namespace std;
using namespace gtsam::symbol_shorthand;
using namespace gtsam;
const double tol = 1e-10;
//******************************************************************************
TEST(LinearlyConstrainedNonlinearOptimizer, Problem1 ) {
// build a quadratic Objective function x1^2 - x1*x2 + x2^2 - 3*x1 + 5
// Note the Hessian encodes:
// 0.5*x1'*G11*x1 + x1'*G12*x2 + 0.5*x2'*G22*x2 - x1'*g1 - x2'*g2 + 0.5*f
// Hence, we have G11=2, G12 = -1, g1 = +3, G22 = 2, g2 = 0, f = 10
HessianFactor lf(X(1), X(2), 2.0 * ones(1, 1), -ones(1, 1), 3.0 * ones(1),
2.0 * ones(1, 1), zero(1), 10.0);
// build linear inequalities
LinearInequalityFactorGraph inequalities;
inequalities.push_back(LinearInequality(X(1), ones(1,1), X(2), ones(1,1), 2, 0)); // x1 + x2 <= 2 --> x1 + x2 -2 <= 0, --> b=2
inequalities.push_back(LinearInequality(X(1), -ones(1,1), 0, 1)); // -x1 <= 0
inequalities.push_back(LinearInequality(X(2), -ones(1,1), 0, 2)); // -x2 <= 0
inequalities.push_back(LinearInequality(X(1), ones(1,1), 1.5, 3)); // x1 <= 3/2
// Instantiate LinearlyConstrainedNLP, pretending that the cost is not quadratic
// (LinearContainerFactor makes a linear factor behave like a nonlinear one)
LinearlyConstrainedNLP lcNLP;
lcNLP.cost.add(LinearContainerFactor(lf));
lcNLP.inequalities = inequalities;
// Compare against a QP
QP qp;
qp.cost.add(lf);
qp.inequalities = inequalities;
// instantiate QPsolver
QPSolver qpSolver(qp);
// create initial values for optimization
VectorValues initialVectorValues;
initialVectorValues.insert(X(1), zero(1));
initialVectorValues.insert(X(2), zero(1));
VectorValues expectedSolution = qpSolver.optimize(initialVectorValues).first;
// instantiate LinearlyConstrainedNonLinearOptimizer
LinearlyConstrainedNonLinearOptimizer lcNLPSolver(lcNLP);
// create initial values for optimization
Values initialValues;
initialValues.insert(X(1), 0.0);
initialValues.insert(X(2), 0.0);
Values actualSolution = lcNLPSolver.optimize(initialValues).first;
DOUBLES_EQUAL(expectedSolution.at(X(1))[0], actualSolution.at<double>(X(1)), tol);
DOUBLES_EQUAL(expectedSolution.at(X(2))[0], actualSolution.at<double>(X(2)), tol);
}
//******************************************************************************
int main() {
TestResult tr;
return TestRegistry::runAllTests(tr);
}
//******************************************************************************