[GRASS-user] v.in.ascii with large files

[Hamish]

[r.in.xyz]

Seb wrote:
> > IIUC, this will create a raster, calculating a statistic for points
> > in each grid cell defined in my current region.  So the trick is to
> > set the grid resolution the same as the input, and then set the
> > statistic to "mean" (hence returning same value as the point)
> > correct?  Thanks.

Yes.

> This does seem right, although something's odd with the display; it
> suggests some land values are the same as those on the ocean.  I
> presume this has to do with the color function.

r.colors rules for etopo2, srtm, and terrain should all break at 0. 
The "elevation" and default "rainbow" rule do not.


> I'd also like to "filter" (exclude) depth values > 0, but haven't
> found the right module.

r.in.xyz:
   zrange   Filter range for z data (min,max)


or use r.maplcalc:
  r.mapcalc 'newmap = if(oldmap > 0, null(), oldmap)'
  r.mapcalc 'sea_mask = if(elev <= 0)'


Hamish