[GRASS-user] How to grep basic statistics from a vector ascii (x, y, z) file and export in a new ascii?

[Markus Neteler]

On Jan 6, 2008 12:12 AM, David Finlayson <dfinlayson at usgs.gov> wrote:
> Your task sounds like it would be best done by a small script or C
> program. Just read the data in a line-at-a-time and check if the
> current line is larger than the previously stored line. At the end of
> the file, print out the largest line (to a file if you have multiple
> results to store). Probably 5 or 6 lines of Perl/Python at most and
> you would be able to read arbitrarily huge files (millions of rows).
> Most other solutions would introduce complexity or unnecessary
> overhead. For lidar data, you may not have enough RAM to hold the
> whole file in memory and the last thing you want to do is attach
> topology to each point before you manipulate it.

Possibly code from r.in.xyz could be recycled for v.univar to operate
on the geometry. I also don't think that you could handle this in R, so
a C implementation is needed.

Markus