vrp-tabu-search/src/example/vrp/Problem.js

Tabu Search Algorithm for Vehicle Routing Problem

/**
 * Created by tnlam on 5/7/15.
 */
var util = require('util');
var assert = require('assert');
var defineClass = require('simple-cls').defineClass;
var Class = require('simple-cls').Class;
var Matrix = require('sylvester').Matrix;
var Vector = require('sylvester').Vector;
var xml2js = require('xml2js');
var fisher_yates_permute = require('../../util/permute.js');

var OProblem = require('../../core/OProblem.js');
var VRPSolution = require('./Solution.js');

var VRP = defineClass({
  name: 'VRP',
  extend: OProblem,

  construct: function (nodes, data, capacity, solution) {
    if (data instanceof Array) {
      data = $M(data);
    }
    if (nodes instanceof Array) {
      nodes = $V(nodes);
    }
    OProblem.call(this, nodes, data, capacity, solution, true);
  },

  methods: {
    valid: function (candidate) {
      //assert(Class.isInstanceOfClass(candidate, 'VRPSolution'));
      //
      //var val = {}; // index from node index to occurance count
      //for (var i = 1; i <= candidate.data.elements.length; i++) {
      //  var idx = candidate.data.e(i);
      //  if (!val[idx]) val[idx] = 1;
      //  else val[idx] += 1;
      //}
      //// once and only once
      //var nodeCount = this.data.elements.length;
      //for (var i = 1; i <= nodeCount; i++)
      //  if (val[i] != 1) return false;
      return true;
    },

    fitness: function (candidate) {

      var total_dist = 0.0;

      for (var i = 0; i < candidate.data.elements.length; i++) {
        for (var j = 0; j < candidate.data.elements[i].length-1; j++) {
          var pre = candidate.data.e(i+1)[j];
          var cur = candidate.data.e(i+1)[j+1];
          //console.log('pre: ' + pre + ', cur: ' + cur);
          //console.log('this.data.e(pre+1,cur+1) = ' + this.data.e(pre+1,cur+1));
          //console.log('data = ' + this.data.e(pre+1, cur+1));
          total_dist = total_dist + this.data.e(pre+1, cur+1);
          //console.log('total_dist = ' + total_dist);
        }
      }
      return total_dist;
    },

    demand: function (route) {
      var value = 0;
      //console.log(route);

      for (var i = 1; i < route.length-1; i++) {
        //console.log(this.nodes.e(i+1));
        //console.log('route[' + route[i] + '] = ' + this.nodes.e(route[i]+1).amount);
        value += this.nodes.e(route[i]+1).amount;
      }
      //console.log(value);

      return value;
    },

    randsol: function () {
      //produce a random solution
      var sol = [];
      for (var i = 1; i <= this.dimension(); i++) sol.push(i);
      fisher_yates_permute(sol);
      var ret = new VRPSolution($V(sol));
      ret.fitness = this.fitness(ret);
      return ret;
    },

    initSolution: function (sol) {
      var ret = new VRPSolution($V($V(sol)));
      ret.fitness = this.fitness(ret);

      return ret;
    },

    dimension: function () {
      //console.log('dimension from Problem.js');
      return this.solution.length; // an array
    }
  },

  statics : {
    parseData: function (raw) {


      return $M(data);
    },

    validData: function (data) {


      return true;
    }

  }
});

module.exports = exports = VRP;