TrainSignManage/WebFrame/bower_components/jvectormap/src/proj.js

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/**
 * Contains methods for transforming point on sphere to
 * Cartesian coordinates using various projections.
 * @class
 */
jvm.Proj = {
  degRad: 180 / Math.PI,
  radDeg: Math.PI / 180,
  radius: 6381372,

  sgn: function(n){
    if (n > 0) {
      return 1;
    } else if (n < 0) {
      return -1;
    } else {
      return n;
    }
  },

  /**
   * Converts point on sphere to the Cartesian coordinates using Miller projection
   * @param {Number} lat Latitude in degrees
   * @param {Number} lng Longitude in degrees
   * @param {Number} c Central meridian in degrees
   */
  mill: function(lat, lng, c){
    return {
      x: this.radius * (lng - c) * this.radDeg,
      y: - this.radius * Math.log(Math.tan((45 + 0.4 * lat) * this.radDeg)) / 0.8
    };
  },

  /**
   * Inverse function of mill()
   * Converts Cartesian coordinates to point on sphere using Miller projection
   * @param {Number} x X of point in Cartesian system as integer
   * @param {Number} y Y of point in Cartesian system as integer
   * @param {Number} c Central meridian in degrees
   */
  mill_inv: function(x, y, c){
    return {
      lat: (2.5 * Math.atan(Math.exp(0.8 * y / this.radius)) - 5 * Math.PI / 8) * this.degRad,
      lng: (c * this.radDeg + x / this.radius) * this.degRad
    };
  },

  /**
   * Converts point on sphere to the Cartesian coordinates using Mercator projection
   * @param {Number} lat Latitude in degrees
   * @param {Number} lng Longitude in degrees
   * @param {Number} c Central meridian in degrees
   */
  merc: function(lat, lng, c){
    return {
      x: this.radius * (lng - c) * this.radDeg,
      y: - this.radius * Math.log(Math.tan(Math.PI / 4 + lat * Math.PI / 360))
    };
  },