[RESOLVED] Longitude/Latitude to Mercator

[luiddog]

I found one php function that changes Lat/Lon to Mercator but it's not very accurate. I also found this javascript that is accurate and simpler. Can someone either reccomend a good function or translate this into php:

<script language="javascript">
        function lonLatToMercator(ll) {
           var lon = ll.lon * 20037508.34 / 180;
           var lat = Math.log(Math.tan((90 + ll.lat) * Math.PI / 360)) / (Math.PI /
           180);
           lat = lat * 20037508.34 / 180;
           return new OpenLayers.LonLat(lon, lat);
        }
</script>

[laserlight]

It depends on what does OpenLayers.LonLat() do. The rest is just simple arithmetic with some trigonometric function calls that are available in the PHP API.

[luiddog]

can you translate:
Math.log(Math.tan((90 + ll.lat) * Math.PI / 360)) / (Math.PI / 180)

thank you

[laserlight]

It would probably be:

log(tan((90 + $ll->lat) * pi() / 360)) / (pi() / 180)

However, I might use an array of two elements instead of an object for $ll, so it may be $ll['lat']. Or perhaps I might provide member functions by which one can access this object's values, thus it would be $ll->lat().

[luiddog]

thank you so much