gtsam/gtsam_unstable/nonlinear/LinearConstraintSQP.cpp

134 lines
5.0 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 LinearConstraintSQP.cpp
* @author Duy-Nguyen Ta
* @author Krunal Chande
* @author Luca Carlone
* @date Dec 15, 2014
*/
#include <gtsam/inference/FactorGraph-inst.h>
#include <gtsam_unstable/linear/QPSolver.h>
#include <gtsam_unstable/nonlinear/LinearConstraintSQP.h>
#include <gtsam_unstable/nonlinear/ConstrainedFactor.h>
#include <iostream>
namespace gtsam {
/* ************************************************************************* */
bool LinearConstraintSQP::isStationary(const VectorValues& delta) const {
return delta.vector().lpNorm<Eigen::Infinity>() < params_.errorTol;
}
/* ************************************************************************* */
bool LinearConstraintSQP::isPrimalFeasible(const LinearConstraintNLPState& state) const {
return lcnlp_.linearEqualities.checkFeasibility(state.values, params_.errorTol);
}
/* ************************************************************************* */
bool LinearConstraintSQP::isDualFeasible(const VectorValues& duals) const {
for(const NonlinearFactor::shared_ptr& factor: lcnlp_.linearInequalities) {
ConstrainedFactor::shared_ptr inequality
= boost::dynamic_pointer_cast<ConstrainedFactor>(factor);
Key dualKey = inequality->dualKey();
if (!duals.exists(dualKey)) continue; // should be inactive constraint!
double dual = duals.at(dualKey)[0];// because we only support single-valued inequalities
if (dual > 0.0) // See the explanation in QPSolver::identifyLeavingConstraint, we want dual < 0 ?
return false;
}
return true;
}
/* ************************************************************************* */
bool LinearConstraintSQP::isComplementary(const LinearConstraintNLPState& state) const {
return lcnlp_.linearInequalities.checkFeasibilityAndComplimentary(
state.values, state.duals, params_.errorTol);
}
/* ************************************************************************* */
bool LinearConstraintSQP::checkConvergence(const LinearConstraintNLPState& state,
const VectorValues& delta) const {
return isStationary(delta) && isPrimalFeasible(state)
&& isDualFeasible(state.duals) && isComplementary(state);
}
/* ************************************************************************* */
VectorValues LinearConstraintSQP::initializeDuals() const {
VectorValues duals;
for(const NonlinearFactor::shared_ptr& factor: lcnlp_.linearEqualities){
ConstrainedFactor::shared_ptr constraint
= boost::dynamic_pointer_cast<ConstrainedFactor>(factor);
duals.insert(constraint->dualKey(), Vector::Zero(factor->dim()));
}
return duals;
}
/* ************************************************************************* */
LinearConstraintNLPState LinearConstraintSQP::iterate(
const LinearConstraintNLPState& state) const {
// construct the qp subproblem
QP qp;
qp.cost = *lcnlp_.cost.linearize(state.values);
qp.equalities.add(*lcnlp_.linearEqualities.linearize(state.values));
qp.inequalities.add(*lcnlp_.linearInequalities.linearize(state.values));
if(params_.verbosity >= NonlinearOptimizerParams::LINEAR)
qp.print("QP subproblem:");
// solve the QP subproblem
VectorValues delta, duals;
QPSolver qpSolver(qp);
VectorValues zeroInitialValues;
for(const Values::ConstKeyValuePair& key_value: state.values)
zeroInitialValues.insert(key_value.key, Vector::Zero(key_value.value.dim()));
boost::tie(delta, duals) = qpSolver.optimize(zeroInitialValues, state.duals,
params_.warmStart);
if(params_.verbosity >= NonlinearOptimizerParams::DELTA)
delta.print("Delta");
// update new state
LinearConstraintNLPState newState;
newState.values = state.values.retract(delta);
newState.duals = duals;
newState.converged = checkConvergence(newState, delta);
newState.iterations = state.iterations + 1;
if(params_.verbosity >= NonlinearOptimizerParams::VALUES)
newState.print("Values");
return newState;
}
/* ************************************************************************* */
std::pair<Values, VectorValues> LinearConstraintSQP::optimize(
const Values& initialValues) const {
LinearConstraintNLPState state(initialValues);
state.duals = initializeDuals();
while (!state.converged && state.iterations < params_.maxIterations) {
if(params_.verbosity >= NonlinearOptimizerParams::ERROR)
std::cout << "Iteration # " << state.iterations << std::endl;
state = iterate(state);
}
if(params_.verbosity >= NonlinearOptimizerParams::TERMINATION)
std::cout << "Number of iterations: " << state.iterations << std::endl;
return std::make_pair(state.values, state.duals);
}
} // namespace gtsam