[Proj] Lat-Lon values under different ellipsoides

[Jan Hartmann]

Frank Warmerdam wrote:
> Jan,
>
> It is not meaningful to use +datum=WGS84 and an ellipse setting that is
> not WGS84.  The +datum=WGS84 expands internally into
> +towgs84=0,0,0 +ellps=WGS84 so your declaration will end up with two ellipse
> settings and which one gets selected will depend on order - a rather unstable
> situation!
>
> Best regards,
>   

OK, I understand. I find the semantics of ellipses and datums in PROJ a 
bit confusing, but I understand how they came about and can work with 
them now.

Jan