MapPointDist.java

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;


/**
 * <code>MapPoint</code> is a utility class that uses the MapPointDist library to evaluate a time and distance matrix
 * using MapPoint.
 * <p>
 * Creation date: Jun 12, 2012 - 4:02:13 PM
 * 
 * @author Victor Pillac, <a href="http://uniandes.edu.co">Universidad de Los Andes</a>-<a
 *         href="http://copa.uniandes.edu.co">Copa</a> <a href="http://www.emn.fr">Ecole des Mines de Nantes</a>-<a
 *         href="http://www.irccyn.ec-nantes.fr/irccyn/d/en/equipes/Slp">SLP</a>
 * @version 1.0
 */
public class MapPointDist {

    /** The separator for CSV files */
    public static String sSeparator    = ";";

    /** Path to the MapPointDist executable */
    public static String sMapPointPath = "../Libraries/mappointdist/MapPointDist.exe";

    /**
     * Generate a file containing all the coordinates, and two files containing the corresponding distance and time
     * matrices
     * 
     * @param coordinates
     *            an array containing the coordinates of all points
     * @param coordFile
     *            the file in which the coordinates will be written
     * @param destFile
     *            the file in which the matrices will be written
     * @param symmetric
     *            {@code true} if the instance is symmetric, {@code false} otherwise
     * @throws IOException
     */
    public static void generateDistanceTimeMatrixFiles(double[][] coordinates, String coordFile,
            String destFile, boolean symmetric) throws IOException {

        // Write the coordinates file
        String formatString = "%s" + sSeparator + "%s" + sSeparator + "%s\n";
        BufferedWriter out = new BufferedWriter(new FileWriter(coordFile));
        out.write(String.format(formatString, "id", "x", "y"));
        for (int i = 0; i < coordinates.length; i++) {
            out.write(String.format(formatString, i, coordinates[i][0], coordinates[i][1]));
        }
        out.flush();
        out.close();
        Process calc = Runtime.getRuntime().exec(
                new String[] { sMapPointPath, coordFile, destFile, "" + symmetric,
                        "" + Runtime.getRuntime().availableProcessors() });
        try {
            System.out.println((
                    "MapPointDist: Calculating distance and time matrix for file "+ coordFile);
            calc.waitFor();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        if (calc.exitValue() != 0) {
            throw new IllegalStateException("The MapPoint subprocess exited with value "
                    + calc.exitValue());
        }
    }

    /**
     * Evaluate the distance and time matrices
     * 
     * @param coordinates
     *            an array containing the coordinates of all points
     * @param coordFile
     *            the file in which the coordinates will be written
     * @param destFile
     *            the file in which the matrices will be written
     * @param symmetric
     *            {@code true} if the instance is symmetric, {@code false} otherwise
     * @return an array of dimension [2][size][size] containing the distances matrix in the first index and the times in
     *         the second
     * @throws IOException
     * @see {@link #generateDistanceTimeMatrixFiles(String, String, String)}
     */
    public static double[][][] evaluateDistanceTimeMatrix(double[][] coordinates, String coordFile,
            String destFile, boolean symmetric) throws IOException {
        generateDistanceTimeMatrixFiles(coordinates, coordFile, destFile, symmetric);

        return loadDistanceTimeMatrix(destFile);
    }

    /**
     * Load a distance and travel time matrix from a file generated by {@code  MapPointDist}.
     * <p>
     * Note that even if the matrices are symmetric, the full matrices will be returned
     * </p>
     * 
     * @param dataFile
     *            the file containing the matrices
     * @return an array of dimension [2][size][size] containing the distances matrix in the first index and the times in
     *         the second
     * @throws IOException
     */
    public static double[][][] loadDistanceTimeMatrix(String dataFile) throws IOException {
        BufferedReader in = new BufferedReader(new FileReader(dataFile));

        int type = 0;
        String row = in.readLine();

        String[] cols = row.split(sSeparator);
        int size = Integer.valueOf(cols[0]);
        boolean symmetric = Boolean.valueOf(cols[1]);

        row = in.readLine();
        double[][][] matrix = new double[2][size][size];
        int i = 0;
        while (row != null) {
            if (row.contains("TIMES"))
                type = 1;
            else if (row.contains("DISTANCES"))
                type = 0;
            cols = row.split(sSeparator);
            if (cols.length > 1) {
                i = Integer.valueOf(cols[0]);
                for (int j = 1; j < cols.length; j++) {
                    if (symmetric) {
                        matrix[type][i][i + j] = Double.valueOf(j);
                        matrix[type][i + j][i] = matrix[type][i][i + j];
                    } else {
                        matrix[type][i][j - 1] = Double.valueOf(j);
                    }
                }
            }
            row = in.readLine();
        }

        return matrix;
    }

}