text: Proj4js.Proj.aeqd = {
  
    init : function() {
      this.sin_p12=Math.sin(this.lat0);
      this.cos_p12=Math.cos(this.lat0);
    },
  
    forward: function(p) {
      var lon=p.x;
      var lat=p.y;
      var ksp;
  
      var sinphi=Math.sin(p.y);
      var cosphi=Math.cos(p.y); 
      var dlon = Proj4js.common.adjust_lon(lon - this.long0);
      var coslon = Math.cos(dlon);
      var g = this.sin_p12 * sinphi + this.cos_p12 * cosphi * coslon;
      if (Math.abs(Math.abs(g) - 1.0) < Proj4js.common.EPSLN) {
         ksp = 1.0;
         if (g < 0.0) {
           Proj4js.reportError("aeqd:Fwd:PointError");
           return;
         }
      } else {
         var z = Math.acos(g);
         ksp = z/Math.sin(z);
      }
      p.x = this.x0 + this.a * ksp * cosphi * Math.sin(dlon);
      p.y = this.y0 + this.a * ksp * (this.cos_p12 * sinphi - this.sin_p12 * cosphi * coslon);
      return p;
    },
  
    inverse: function(p){
      p.x -= this.x0;
      p.y -= this.y0;
  
      var rh = Math.sqrt(p.x * p.x + p.y *p.y);
      if (rh > (2.0 * Proj4js.common.HALF_PI * this.a)) {
         Proj4js.reportError("aeqdInvDataError");
         return;
      }
      var z = rh / this.a;
  
      var sinz=Math.sin(z);
      var cosz=Math.cos(z);
  
      var lon = this.long0;
      var lat;
      if (Math.abs(rh) <= Proj4js.common.EPSLN) {
        lat = this.lat0;
      } else {
        lat = Proj4js.common.asinz(cosz * this.sin_p12 + (p.y * sinz * this.cos_p12) / rh);
        var con = Math.abs(this.lat0) - Proj4js.common.HALF_PI;
        if (Math.abs(con) <= Proj4js.common.EPSLN) {
          if (this.lat0 >= 0.0) {
            lon = Proj4js.common.adjust_lon(this.long0 + Math.atan2(p.x , -p.y));
          } else {
            lon = Proj4js.common.adjust_lon(this.long0 - Math.atan2(-p.x , p.y));
          }
        } else {
          con = cosz - this.sin_p12 * Math.sin(lat);
          if ((Math.abs(con) < Proj4js.common.EPSLN) && (Math.abs(p.x) < Proj4js.common.EPSLN)) {
             //no-op, just keep the lon value as is
          } else {
            var temp = Math.atan2((p.x * sinz * this.cos_p12), (con * rh));
            lon = Proj4js.common.adjust_lon(this.long0 + Math.atan2((p.x * sinz * this.cos_p12), (con * rh)));
          }
        }
      }
  
      p.x = lon;
      p.y = lat;
      return p;
    } 
  };
  