[GRASS-user] LIDAR Data

[Roberto Antolin]

Hi all,

Frank Broniewski ha scritto:
> Hi 
> 
> There was a bug in grass that was caused by adding the mapset with the @ 
> paramter to the map. From which date is your cvs version? The fix was 
> submitted to the cvs last friday.

 >>GRASS 6.3.cvs (Morbach):~ > v.lidar.growing
 >>input=morbach55156_edge at PERMANENT output=morbach55156_grow
 >>input_first=morbach55156
 >>database=/home/seeger/Documents/GRASSDATA/Morbach/PERMANENT/dbf/
 >>driver=dbf tj=0.2 td=0.6
 >>dbmi: Protocol error
 >>ERROR: It was impossible open table

Maybe that solution pointed out by Frank is correct, but anyway I've 
also submitted a patch to v.lidar.growing command. Now it works without 
db and driver parameters. I also change "input_first" to "first". It is 
still clear and it is shorter :)

It should work now. I tested v.lidar.grow with my lidar datasets and it 
works perfectly. So, you should update your CVS local version.

>>Another question. How many points can be handled with grass and these
>>modules (or grass vector files in general)?

It depends. Without topology, people at my group is able to work with 
more than 9 millions of points without problems. I know some people 
around here has worked with 25 millions of points.

With topology, it depends on your computer. We have 2GB RAM and 4GB 
swap, and we are able to work with up to 8 millions of points. After 
that it goes out of memory.

Anyway, v.lidar.* don't ask and don't build topology and this helps a 
lot. Unfortunately, some useful vector commands within grass make use of 
   the topology. And

Regards,
Roberto.

-- 
Roberto Antolín Sánchez
Politecnico di Milano – Polo Regionale di Como
(Laboratorio di Geomatica V2.8)
Via Valleggio, 11 – 22100 Como, Italy
tel: +39 031 332 7533 || fax: +39 031 332 7519
email: roberto.antolin at polimi.it