[GRASS5] Re: vector point dataset

[Gordon Keith]

On Thu, 18 Nov 2004 10:07, Brent Wood wrote:
> I do occasionally work with multibeam data, tho that is peripheral at
> present. I use Walter Smith's new S&S/GEBCO blended global topographic
> grid for much of my bathymetric background work, where it involves regions
> NIWA does not have it's own data. I think there are around 230,000,000
> points/cells in this dataset (1 minute grid) I don't know if it is
> published yet, but was posted on the GMT list.

I use the Australian bathymetry and topography grid, .01 degree data for 8-52 
S 102-172E, about 30M points, for backgrounds. Grass handles this data fairly 
well.

Importing it was very straightforward as it is already gridded, so v.to.rast 
works fine so long as the region is set correctly. 
g.region n=-7.995 s=52.005 e=101.995 w=172.005 res=.01

v.to.rast works fairly quickly. The other methods of creating a raster from 
points don't seem to cope at all with large data set.

Actually, looking back, I used v.to.rast on the 20 different 1.5M point files 
the data came in. I can't remember if that was just because the data came 
that way or grass had problems with a single 30M point file.

Regards
Gordon

-- 

Gordon Keith
Programmer/Data Analyst
Marine Acoustics
CSIRO Marine Research
http://www.marine.csiro.au

We love because God first loved us.
  -- 1 John 4:19