[GRASS-user] Leics: No display in Map Display 1

Hamish hamish_b at yahoo.com
Tue May 27 09:23:13 EDT 2008

H.S.Rai wrote:
> On using GRASS 6.2.2, for leics data (probably which is for
> GRASS 5.2), I get first error of missing proj_info:
> ============
> PROJ_INFO file not found for location leics
> PROJ_INFO file not found for location leics
>     while executing
> "close $input"
>     (procedure "MapCanvas::runprograms" line 39)
>     invoked from within
> "MapCanvas::runprograms $mon [expr {$mymodified !=
> 0}]"
>     (procedure "MapCanvas::drawmap" line 38)
>     invoked from within
> "MapCanvas::drawmap $mon"
>     (procedure "MapCanvas::display_server" line
> 9)
>     invoked from within
> "MapCanvas::display_server"
>     ("after" script)
> ===============
> How to remove it or does it have any bearing?
> In Map Display 1, I could not get display of any raster
> layer, however
> d.mon start=x0
> d.rast image
> works fine i.e in Monitor X0.
> How to get display in Map Display 1?

Right. Looking at the Leics's PERMANENT mapset I see that is has no PROJ_INFO file. That is perfectly legal for a simple XY location which is unprojected. The GUIs should be able to handle that, as that is the basis of rectifying scanned images. (but don't know if the wx GUI does or not)

Looking in the leics DEFAULT_WIND, WIND and cellhd/* files I see that the proj: listed there is "1", which include/gis.h tells us is PROJECTION_UTM. (nb. those files report "zone: 0" while UTM starts at 1; UK is in zone 30)

I am not sure what projection is used. Maybe someone who lives close to Leicestershire knows. The extents look like:
north:      322000
south:      310000
east:       456000
west:       444000

or perhaps it is something custom?

Lacking that info, if you like to convert it to a simple XY location, edit WIND, DEFAULT_WIND, and all cellhd/ files to all say "proj: 0" instead of "proj: 1". It should work then.

The command line is less picky about that info being broken I guess.

If you discover what projection they used you can change the "0"s to "99"s and set the projection with g.setproj to create the PROJ_INFO file.

I take it by now you've found the Optimal Routing chapter in the tutorial. With GRASS 6 there are now vector equivalents to the raster modules, but one method at a time...

r.cost + r.drain and MASKs will be the main things to work with I think.



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