arcgis server 中Web墨卡托投影與WGS-84坐標的轉換

arcgis server 中Web墨卡托投影坐標與WGS-84坐標的轉換

   //經緯度轉墨卡托  
 function lonlat2mercator(lonlat){  
var mercator={x:0,y:0};  
var x = lonlat.x *20037508.34/180;  
 var y = Math.log(Math.tan((90+lonlat.y)*Math.PI/360))/(Math.PI/180);  
 y = y *20037508.34/180;  
   mercator.x = x;  
   mercator.y = y;  
  return mercator ;  
  }  
   //墨卡托轉經緯度  
   function mercator2lonlat(mercator){  
   var lonlat={x:0,y:0};  
   var x = mercator.x/20037508.34*180;  
   var y = mercator.y/20037508.34*180;  
   y= 180/Math.PI*(2*Math.atan(Math.exp(y*Math.PI/180))-Math.PI/2);  
  lonlat.x = x;  
  lonlat.y = y;  
  return lonlat;  
  }  
 //墨卡托轉經緯度定位  
 var dx = sGeometry.x / 20037508.34 * 180;  
 var dy = sGeometry.y / 20037508.34 * 180;  
var M_PI = Math.PI;  
 dy = 180 / M_PI * (2 * Math.atan(Math.exp(dy * M_PI / 180)) - M_PI / 2);  
 //地理坐標x為:122.10626710683903  
 //地理坐標y為:37.48735577057014  
 // x=dx;  
 // y=dy;