 
 
 
 
 
 
mercator, robinsen projections
- To: mathgroup at smc.vnet.net
- Subject: [mg56104] mercator, robinsen projections
- From: Edward Peschko <esp5 at pge.com>
- Date: Fri, 15 Apr 2005 04:48:08 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
hey all, 
    I was wondering if people had some pointers on how to translate Mercator 
Latitude/Longitude points to Robinsen (or other projections.)
Example:
    suppose I had a robinsen graph of the world, which is on a flat, 2D graph.
I'd like to 'pick points' off of this axis, and turn them into equivalent points 
on a mercator graph. And I'd like to go vice versa.
Is there a simple, mathematica function or package that will do this, eg:
	Mercator[.1,.1]
which takes the linear representation of Mercator 
	(
		x == 0 => corresponds to zero meridian, 
		x == -1 => corresponds to -180 longitude, 
		y == 0 => corresponds to equator, 
		y == -infinity => corresponds to the south pole
	)
and turns it into a latitude/longitude representation? Ultimately, I'd like to be 
able to say something like:
	Robinson_Coords[
		Mercator_LatLong[.1,.1]
	];
to convert from the flat, Mercator version of a map to the Robinson coordinates,
and
	Mercator_Coords[
		Robinson_LatLong[.1,.1]
	]
to go the other way around.
There's got to be a projections package out there somewhere, or is this a 
particular wheel I need to reinvent?
Thanks much,
Ed
	

