[GRASS-user] r.patch: number of rasters

[Markus Neteler]

On Tue, Nov 2, 2010 at 4:41 PM,  <razmjooeis at faunalia.co.uk> wrote:
> Hi Markus
>
> Many thanks for your response. In the past versions, the patched raster
> used to have an odd values.

No, this is rather impossible (perhaps you refer to the odd number of pixels
in a moving raster window).

> I use Grass 6.4 from Ubuntu 10.10 64 bit repo.

Master question: how many files do you plan to patch?

Markus

> Cheers
> Sab
>
>
>
>> On Tue, Nov 2, 2010 at 2:03 PM,  <razmjooeis at faunalia.co.uk> wrote:
>>> Dear all
>>>
>>> Is there a limit on the number of rasters for r.patch?
>>
>> How funny, we had the same question at the same time... :)
>> From GRASS 6.4+ there is no more limit despite the limit of open files per
>> process (which depends on the operating system; for Linux it is
>> usually 1024 files).
>>
>> To increase that:
>>
>> The limit of open files per process was reached (64bit Linux: 1024
>> files; ulimit -n)
>> To overcome this limit, the "nofile" parameter needs to be increased in
>> the
>> /etc/security/limits.conf
>> file. Here an increase to 1500 files (use * instead of neteler to aply
>> it to all users):
>>
>> #<domain>      <type>  <item>         <value>
>> neteler               hard    nofile          1500
>>
>>
>> --------------------
>> But myself, I got troubles when having registered the maps with
>> r.external:
>>
>> GRASS 6.4.1svn (patUTM32):~ > r.patch in=`g.mlist type=rast
>> pattern=dtm00* sep=comma mapset=dtm_1m_external` out=dtm_trentino_2m
>> ERROR 1:
>> TIFFOpen:/geodata/base_cartography/pat_DTM_LIDAR_2007_UTM_WGS84/geotiffs/dtm000501.tif:
>> Too many open files
>> WARNING: Unable to open
>>        '/grassdata/patUTM32/dtm_1m_external/cell_misc/dtm000501/f_format'
>> WARNING: quantization file [dtm000501] in mapset [dtm_1m_external] missing
>> WARNING: Unable to open raster map <dtm000502 at dtm_1m_external>
>> ERROR: One or more input raster maps not found
>>
>> So far I could not find out the reason. Here I am using 500 files
>> registered
>> with r.external.
>>
>> Help welcome,
>> Markus
>>
>
>
>