PreProcessEuclidean.java

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/* *********************************************************************** *
 * project: org.matsim.*
 * PreProcessEuclidean.java
 *                                                                         *
 * *********************************************************************** *
 *                                                                         *
 * copyright       : (C) 2007 by the members listed in the COPYING,        *
 *                   LICENSE and WARRANTY file.                            *
 * email           : info at matsim dot org                                *
 *                                                                         *
 * *********************************************************************** *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *   See also COPYING, LICENSE and WARRANTY file                           *
 *                                                                         *
 * *********************************************************************** */

package org.matsim.core.router.util;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.matsim.api.core.v01.network.Link;
import org.matsim.api.core.v01.network.Network;
import org.matsim.core.utils.geometry.CoordUtils;

public class PreProcessEuclidean extends PreProcessDijkstra {

    private static final Logger log = LogManager.getLogger(PreProcessEuclidean.class);

    // Must be initialized to MAX_VALUE, otherwise updateMaxFreeSpeed(...) does
    // not change minTravelCostPerLength
    private double minTravelCostPerLength = Double.POSITIVE_INFINITY;

    protected TravelDisutility costFunction;

    public PreProcessEuclidean(final TravelDisutility costFunction) {
        this.costFunction = costFunction;
    }

    @Override
    public void run(final Network network) {
        super.run(network);

        if (!checkLinkLengths(network)) {
            log.warn("There are links with stored length smaller than their Euclidean distance in this network. Thus, A* cannot guarantee to calculate the least-cost paths between two nodes.");
        }

        updateMinTravelCostPerLength(network);
    }

    private void updateMinTravelCostPerLength(final Network network) {
        for (Link link : network.getLinks().values()) {
            double minCost = this.costFunction.getLinkMinimumTravelDisutility(link) / link.getLength();
            if (getMinTravelCostPerLength() > minCost) {
                setMinTravelCostPerLength(minCost);
            }
        }
    }

    private boolean checkLinkLengths(final Network network) {
        for (Link link : network.getLinks().values()) {
            double linkLength = link.getLength();
            double eucDist = CoordUtils.calcEuclideanDistance(link.getFromNode().getCoord(), link.getToNode().getCoord());
            if (linkLength < eucDist) {
                if (log.isDebugEnabled()) {
                    log.debug("link " + link.getId() + " has length " + linkLength + " which is smaller than the euclidean distance " + eucDist);
                }
                return false;
            }
        }
        return true;
    }

    void setMinTravelCostPerLength(final double maxFreeSpeed) {
        this.minTravelCostPerLength = maxFreeSpeed;
    }

    public double getMinTravelCostPerLength() {
        return this.minTravelCostPerLength;
    }

    public TravelDisutility getCostFunction() {
        return this.costFunction;
    }
}