Greedy.cpp

/*********************************************************************
 * Software License Agreement (BSD License)
 *
 *  Copyright (c) 2020,
 *  Max Planck Institute for Intelligent Systems (MPI-IS).
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions and the following
 *     disclaimer in the documentation and/or other materials provided
 *     with the distribution.
 *   * Neither the name of the MPI-IS nor the names
 *     of its contributors may be used to endorse or promote products
 *     derived from this software without specific prior written
 *     permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 *  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 *  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 *  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 *  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 *  ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY OF SUCH DAMAGE.
 *********************************************************************/
 
/* Author: Andreas Orthey */
 
#include <ompl/multilevel/datastructures/importance/Greedy.h>
 
ompl::multilevel::BundleSpaceImportanceGreedy::BundleSpaceImportanceGreedy(BundleSpaceGraph *graph) : BaseT(graph)
{
    if (epsilon <= 0)
    {
        OMPL_WARN("Epsilon is zero.");
    }
}
 
double ompl::multilevel::BundleSpaceImportanceGreedy::getLevelConstant()
{
    const double k = bundleSpaceGraph_->getLevel() + 1;
    BundleSpace *cur = bundleSpaceGraph_;
 
    double K = k;
    while (cur->hasSolution() && cur->hasParent())
    {
        cur = cur->getParent();
        K++;
    }
 
    double f = (k > 1 ? powf(epsilon, K - k) - powf(epsilon, K - k + 1) : powf(epsilon, K - k));
 
    return f;
}
 
double ompl::multilevel::BundleSpaceImportanceGreedy::eval()
{
    const double f = getLevelConstant();
    double N = (double)bundleSpaceGraph_->getNumberOfVertices();
    return 1.0 / (N / f + 1);
}