[GRASS-web] importing multiples las files in grass gis (windows)

[Markus Neteler]

Hello Rengifo Ortega,

please note that this is a perfect question for the grass-user mailing list:

http://lists.osgeo.org/mailman/listinfo/grass-user

(here you are on the Web site list).

Some quick answers below:

On Fri, Apr 11, 2014 at 10:38 PM, Rengifo Ortega <rengifoo at yahoo.de> wrote:
> Hello dear grass developers
> I am currently working with a project, where I need to build a DEM with a
> 2x2 meters resolution.  I have around 800 las files with 0.7 and 2
> points/sqm, which I already converted to text format using the las2txt
> command as explained at liblas.org.

Hint:
You may just remain in LAS/LAZ format when switching to GRASS GIS 7,
there are now r.in.lidar and v.in.lidar.

http://grass.osgeo.org/grass70/manuals/r.in.lidar.html
http://grass.osgeo.org/grass70/manuals/v.in.lidar.html

>  So, I intend to import all 800 .txt files into GRASS GIS at once, if
> possible, in order to create my DEM from the entire area of study.
> However, every time I try to import even one txt file in  Grass Gis, by
> using the r.in.ixyz , I get the  well- known allocation memory message
> (ERROR: G_calloc: unable to allocate.... )

GRASS GIS 7 is now "large file" capable also for vector data. The only
limitation per map is 2^31 - 1 (about 2 billion) features per vector
map (see
http://grasswiki.osgeo.org/wiki/GRASS_GIS_Performance#Vector_geometry
).

See also
http://grass.osgeo.org/news/32/15/GRASS-GIS-7-0-0-beta1/
http://trac.osgeo.org/grass/wiki/Release/7.0.0beta-News

> So, wrapping all  together  what I want to do is:
> 1)      To import all 800 files at once, instead of importing one by one. I
> know it is possible in linux, but I have not figured it out how to do it in
> the cmd (dos) windows.

You are at time
- limited by GRASS GIS 6
- limited due to the absence of r.in.lidar and v.in.lidar in G6.

Hence pls consider to try the new version.

> Technical settings of my work environment:
>
> Grass GIS 6.4 running on windows 7, installed using the  osGeo4W installer,
> fully operative.
> RAM 6GB
> The las data  is over 750 GB. Lasdata was pre-processed using lastools. Only
> class 2 (bare ground) was kept.
>
> I hope someone can drop some lines about how to do this in a windows
> environment. So, far I only found  linux examples, which  uses eval, flags
> and pipes. All this  is not applicable in  cmd.

Indeed, that's why r.in.lidar and v.in.lidar have been developed.


Regards,

Markus Neteler

-- 
http://courses.neteler.org/
http://gis.cri.fmach.it/