gtsam/gtsam_unstable/nonlinear/LinearInequalityFactorGraph.cpp

/* ----------------------------------------------------------------------------

 * 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    LinearInequalityFactorGraph.cpp
 * @author  Duy-Nguyen Ta
 * @author  Krunal Chande
 * @author  Luca Carlone
 * @date    Dec 15, 2014
 */

#include <gtsam_unstable/nonlinear/LinearInequalityFactorGraph.h>
#include <gtsam_unstable/nonlinear/ConstrainedFactor.h>

namespace gtsam {

/* ************************************************************************* */
InequalityFactorGraph::shared_ptr LinearInequalityFactorGraph::linearize(
    const Values& linearizationPoint) const {
  InequalityFactorGraph::shared_ptr linearGraph(new InequalityFactorGraph());
  for(const NonlinearFactor::shared_ptr& factor: *this) {
    JacobianFactor::shared_ptr jacobian = boost::dynamic_pointer_cast<JacobianFactor>(
        factor->linearize(linearizationPoint));
    ConstrainedFactor::shared_ptr constraint
        = boost::dynamic_pointer_cast<ConstrainedFactor>(factor);
    linearGraph->add(LinearInequality(*jacobian, constraint->dualKey()));
  }
  return linearGraph;
}

/* ************************************************************************* */
bool LinearInequalityFactorGraph::checkFeasibilityAndComplimentary(
    const Values& values, const VectorValues& dualValues, double tol) const {

  for(const NonlinearFactor::shared_ptr& factor: *this) {
    NoiseModelFactor::shared_ptr noiseModelFactor
        = boost::dynamic_pointer_cast<NoiseModelFactor>(factor);
    Vector error = noiseModelFactor->unwhitenedError(values);

    // Primal feasibility condition: all constraints need to be <= 0.0
    if (error[0] > tol)
      return false;

    // Complimentary condition: errors of active constraints need to be 0.0
    ConstrainedFactor::shared_ptr constraint
        = boost::dynamic_pointer_cast<ConstrainedFactor>(factor);
    Key dualKey = constraint->dualKey();

    // if dualKey doesn't exist in dualValues, it must be an inactive constraint!
    if (!dualValues.exists(dualKey))
      continue;

    // for active constraint, the error should be 0.0
    if (fabs(error[0]) > tol)
      return false;
  }

  return true;
}

}