source: branches/FitnessLandscapeAnalysis/VRPProblemAnalyzer/DepotExcentricityCalculator.cs @ 12015

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace VRPProblemAnalyzer {

  public class DepotExcentricityCalculator {

    public static double Geographic(double[,] vertices) {
      var customers = Utils.MatrixToPointList(vertices);
      var depot = customers[0];
      customers.RemoveAt(0);
      var minX = customers.Min(c => c.X);
      var minY = customers.Min(c => c.Y);
      var maxX = customers.Max(c => c.X);
      var maxY = customers.Max(c => c.Y);
      var rangeX = maxX - minX;
      var rangeY = maxY - minY;
      var center = new PointD(minX + rangeX/2, minY + rangeY/2);
      Console.WriteLine("Geographic {0} -> {1} = {2}", depot, center, depot.DistanceTo(center));
      return depot.DistanceTo(center);
    }

    public static double DistanceCentroid(double[,] vertices) {
      var customers = Utils.MatrixToPointList(vertices);
      var depot = customers[0];
      customers.RemoveAt(0);
      var center = new PointD(
        customers.Select(c => c.X).Average(),
        customers.Select(c => c.Y).Average());
      Console.WriteLine("Distance {0} -> {1} = {2}", depot, center, depot.DistanceTo(center));
      return depot.DistanceTo(center);
    }

    public static double DemandDistanceCentroid(double[,] vertices, double[] demands) {
      var factor = demands.Sum()/demands.Length;
      var customers = Utils.MatrixToPointList(vertices).Zip(demands, (c, d) => new {c.X, c.Y, D = d/factor}).ToList();
      var depot = customers[0];
      customers.RemoveAt(0);
      var center = new PointD(
        customers.Select(c => c.X*c.D).Average(),
        customers.Select(c => c.Y*c.D).Average());
      Console.WriteLine("Demand {0} -> {1} = {2}", depot, center, new PointD(depot.X, depot.Y).DistanceTo(center));
      return new PointD(depot.X, depot.Y).DistanceTo(center);
    }
  }
}