[GRASS5] Re: [GRASSweb-list]Error from r.proj

Paul Kelly paul-grass at stjohnspoint.co.uk
Mon Apr 21 10:21:30 EDT 2003


On Sat, 19 Apr 2003, Ray D Wright wrote:

> Hello,
> I'd be very grateful if someone could tell me what to do to get around
> an error from r.proj!
> I am trying to reproject a raster file I created in a Polar
> Stereographic location "EMEP" into a new Lambert conformal location.
> I start up Grass5 in the new location and then try to use r.proj - see
> below - to re-project the old raster file in the new projection, which
> is Lambert conformal.
> GRASS:/usr/local/grass5/data/EMEP > r.proj input=no2-2000 location=EMEP
> cannot initialize pj
> cause: elliptical usage required

The cryptic error message will have emanated from PROJ.4, the co-ordinate
system translation library used by GRASS. It probably means something was
missing in the projection parameters passed to it by GRASS, possibly a
problem with the details of the ellipsoid the projection is based on (in
this case the Polar Stereographic location as r.proj has reported a
problem with the input map).

You can view these parameters with the command g.projinfo and change them
with g.setproj or by editing the 'PROJ_INFO' file in the 'PERMANENT'
mapset directory under the location in the GRASS database. The most recent
CVS version of r.proj will print the parameters for both the input and
output locations to the screen.

Two options to try next:
A) Post a copy of the output of g.projinfo to this list and there may be
something obviously noticeable wrong with it.
B) Try upgrading to the latest CVS version of GRASS where there have been
several improvements in the projection handling and see if you get
anywhere with that.

Paul Kelly

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