Given an svg map like this one on Wikimedia, I'd like to add a circle centered on New York City (or any given latitude/longitude) by adding a line like this to the svg file:
<circle cx="X" cy="Y" r="5" />
The hard part of course is knowing what X and Y should be. New York's latitude and longitude are 40.7127° N, 74.0059° W. Is there a way to convert this to an x,y coordinate that is consistent with the given svg file? The file doesn't say what projection was used, so I imagine this can only be done by guessing what the projection is.
