[GIS] Project Point using ArcGIS API for JavaScript

arcgis-javascript-apicoordinate system

I've to project geometry point

Point(1657272, 6100874) with NZTM, WKID: 2193

But, point is shown near Austria, not on NewZealand maps. I've converted above coordinates to geographic, still its not giving correct results. Following is my code:

var mp = esri.geometry.webMercatorToGeographic(new esri.geometry.Point(1657272, 6100874, new esri.SpatialReference({ wkid: 2193 })));

map = new Map("mapDiv",
center: [mp.x,mp.y],
zoom: 5,
basemap: "streets" });

on(map, "load", addGraphic);

function addGraphic() {
map.graphics.add(new esri.Graphic(mp,
new esri.symbol.SimpleMarkerSymbol().setColor(new dojo.Color([255, 0, 0, 0.5])) ) ) }

Please tell me what's wrong with above code and why it's not projecting point on correct area.

EDITED CODE

var map, gsvc;

require([
"esri/map", "esri/graphic", "esri/symbols/SimpleMarkerSymbol",
"esri/tasks/GeometryService", "esri/tasks/ProjectParameters",
"esri/SpatialReference", "esri/InfoTemplate", "dojo/dom", "dojo/on",
"dojo/domReady!"
], function(
Map, Graphic, SimpleMarkerSymbol,
GeometryService, ProjectParameters,
SpatialReference, InfoTemplate, dom, on
) {

   map = new Map("map", {
      basemap: "streets",
      center: [174.605369, -37.120276],
      zoom: 5
    });

   gsvc = new GeometryService("http://tasks.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer");

   on(map, "load", projectToLatLong);

   function projectToLatLong() {
        map.graphics.clear();

        m_mapPoint = [];
        m_mapPoint[0] = new esri.geometry.Point(1657272, 6100874, new esri.SpatialReference({ wkid: 2193 }));
        var outSR = new SpatialReference(3857);

        var symbol = new SimpleMarkerSymbol(SimpleMarkerSymbol.STYLE_CIRCLE, 20,
                      new SimpleLineSymbol(SimpleLineSymbol.STYLE_SOLID,
                          new Color([255, 0, 0]), 2), new Color([0, 0, 0, 0])
                      )          
        var graphic = new Graphic(m_mapPoint, symbol);
        map.graphics.add(graphic);

        var params = new esri.tasks.ProjectParameters();
        // add array of points
        params.geometries = m_mapPoint;
        // Output Spatial Reference in lat/long (wkid 3857 )           
        params.outSR = outSR;
        gsvc.project(params);
    }
  });
</script>

Please check updated code. Still point is not projecting.

Best Answer

From https://developers.arcgis.com/javascript/jsapi/esri.geometry.webmercatorutils-amd.html#webmercatortogeographic:

Translates the given Web Mercator coordinates to Longitude and Latitude. By default the returned longitude is normalized so that it is within -180 and +180.

But your NZTM coordinates are not in webMercator units. You have to convert them from EPSG:2193 to EPSG:3857 to use this function.

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