[OpenLayers-Users] What is the relationship between zoom level and longitude/latitude

[Kenneth Skovhede, GEOGRAF A/S]

There is a function just for that:
http://dev.openlayers.org/releases/OpenLayers-2.8/doc/apidocs/files/OpenLayers/Map-js.html#OpenLayers.Map.zoomToExtent

If you need the value, you can call this:
http://dev.openlayers.org/releases/OpenLayers-2.8/doc/apidocs/files/OpenLayers/Map-js.html#OpenLayers.Map.getZoomForExtent

You can examine the code if you are interested in the inner workings of 
calculating a zoom level from a rectangle.

Regards, Kenneth Skovhede, GEOGRAF A/S




Adrian Popa skrev:
> Hello everybody.
>
> I'm trying to zoom to view an area for which I have the minimum and 
> maximum longitude/latitude. Basically I would like to zoom in to see a 
> rectangle with known coordinates. I already calculated the center of 
> this rectangle - so that's not a problem - the map centers beautifully 
> to that.
>
> The problem is: I have to find out which minimum zoom setting would 
> allow my area to be fully visible - so I need to choose a zoom setting. 
> There must be a relationship between the difference in longitude (or 
> latitude) to a zoom level.
>
> I wonder if anyone knows this relationship - or should I determine it 
> empirically.
>
> Thank you.
>
> By the way, my map is using spherical mercator projection, but my 
> coordinates are in longitude/latitude (although there is no problem in 
> converting them...).
>
>