[MetaCRS] Why GCTP in Proj4js?

[Mike Adair]

It is simply for historical reasons: the initial implementation of the 
forward/inverse methods from the MapBuilder project used the GCTPC code 
as a base because it was easier to port.  In theory they should give the 
same result but I've converted one or two of those to the PROJ4 code 
base because they had different algorithms for spherical/elliptical 
spheroids.

Mike

Martin Davis wrote:
> Proj4js appears to have some projection algorithms taken from GCTP, 
> rather than PROJ4.  I'm curious about the reason for this.  Are they 
> more accurate?  Or easier to port or maintain?
>

-- 
   Michael Adair
   Senior Software Architect
   DM Solutions Group Inc.

   Office: (613) 565-5056 x26
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