[GRASS-user] problem in v.drape command

[Markus Neteler]

Jerry Nelson wrote on 07/09/2007 04:18 PM:
> Is this a place where the error message could be made clearer? For example,
> could it add possible sources of the problem such as the one Markus
> indicated, or are there too many possibilities for ways to do it wrong?
>
>   
Jerry,

I agree that the error isn't helpful and stumbled myself over it several
times.
It is buried in the core of GRASS:
cd grass63/lib/gis/
grep 'is outside region' *
get_row.c:      G_warning(_("[%s in %s] - read request for row %d is
outside region"),
get_row.c:      G_warning(_("[%s in %s] - read request for row %d is
outside region"),

so I don't know how to link it to v.drape. At least, I have expanded the
manual page to

########## snip ##########
ERROR MESSAGES
If the following error message appears

 WARNING: [demname in mapset] - read request for row -1 is outside region
 ERROR: problem reading raster cell file

it indicates that the vector map is spatially larger than the raster
map. To avoid this problem, the vector map needs to be clipped to the
raster map extent, for example:

g.region rast=demname
v.in.region clipbox
v.overlay ain=clipbox bin=vectmap out=vectmap_clipped op=and
v.drape vectmap_clipped out=vectdrape rast=demname

Then /v.drape/ should perform the draping.
########## snip ##########

Hopefully helpful,
Markus

> -----Original Message-----
> From: grassuser-bounces at grass.itc.it [mailto:grassuser-bounces at grass.itc.it]
> On Behalf Of Markus Neteler
> Sent: Monday, July 09, 2007 8:43 AM
> To: grassuser at grass.itc.it
> Subject: Re: [GRASS-user] problem in v.drape command
>
> temiz wrote on 07/09/2007 07:26 PM:
>   
>> hello
>>
>> when I entered this command, I received following error message:
>>
>> ~~~~~~~~~~~~
>> GRASS 6.3.cvs (bartin):~ > v.drape in=jeo3 out=jeo3d2 rast=eldene
>> type=face --overwrite
>> defaulting to nearest neighbor sampling
>> WARNING: The vector 'jeo3d2' already exists and will be overwritten.
>> WARNING: [eldene in orkun] - read request for row -1 is outside region
>> ERROR: problem reading raster cell file
>> [Raster MASK present]
>> ~~~~~~~~~~~~~
>>
>> can you tell me what the problem may be ?
>>     
> The problem is that the vector map is bigger than the raster map.
> You need to use
>
> g.region rast=dem
> v.in.region box
> v.overlay ... with box and your vector map to restrict the vector map to
> the DEM size
> v.drape ... with the reduced vector map.
>
> Markus
>
> ------------------
> ITC -> dall'1 marzo 2007 Fondazione Bruno Kessler
> ITC -> since 1 March 2007 Fondazione Bruno Kessler
> ------------------
>
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>
>   


------------------
ITC -> dall'1 marzo 2007 Fondazione Bruno Kessler
ITC -> since 1 March 2007 Fondazione Bruno Kessler
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