set map center in leaflet with 3857 lat/lon

Question

I'm trying to set map center with lat/lon of 3857 projection in leaflet. By using lat/lon of projection 4326 its working fine.

var map = L.map('map', {
        crs: L.CRS.EPSG3857
    }).setView([51.40457186188496, -2.3741738081973844], 13);

But it dose not working if i provide 3857 lat/lon.

var map = L.map('map', {
            crs: L.CRS.EPSG3857
        }).setView([6693172.2381477, -264291.81938326], 13);

Please help me where i am wrong.

Thanks

Answer 1

Leaflet's API uses lat/lng for all its operations, so you should never use projected coordinates when calling Leaflet.

If you have projected coordinates, which strictly speaking isn't latitude and longitude , you can turn them into lat/lng by unprojecting them. Since current stable versions of Leaflet has a slightly different definition of EPSG:3857, you will have to divide your coordinate by the EPSG:3857's sphere radius. Also, your coordinate appears to have x and y swapped. Anyway, here's code to perform the conversion:

function toLatLng(x, y, map) { var projected = L.point(y, x).divideBy(6378137); return map.options.crs.projection.unproject(projected); }

Call it like this:

var latLng = toLatLng(6693172.2381477, -264291.81938326, myMap);

You could also work with a library like Proj4js to do projection/unprojection: http://proj4js.org/