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

[Saber Razmjooei]

I am having about 700 LiDAR tiles (~4 GB). Did it a couple of hours ago
and all worked well...the DTM looks as I expected!

The problem I had last year when I did it last, there were 1000+, values
for one tile were changed. Never investigated the problem. Simply
changed the region and things worked smoothly.

Many thanks 
Sab

On Tue, 2010-11-02 at 16:54 +0100, Markus Neteler wrote:
> 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
> >>
> >
> >
> >