[GRASS-dev] r.in.lidar tuning

[Markus Neteler]

On Mon, May 19, 2014 at 6:30 AM, Hamish <hamish.webmail at gmail.com> wrote:
>> [ wish for r.in.lidar: ]
>> ...
>> >>>     filter   Only import points of selected return type
>> >>>               If not specified, all points are imported
>> >>>              options: first,last,mid
>> >>>
>> >>> which would be great for r.in.lidar as well to avoid that I need
>> >>> to split the file with las2las beforehand.
>
> Markus Neteler wrote:
>> I have implemented that now in
>> http://trac.osgeo.org/grass/changeset/60247/grass/trunk/raster/r.in.lidar
>>
>> (hope I got it right over from v.in.lidar)
>
>
> Hi,
>
> you might look at the vrange= "Filter range for alternate value column data (min,max)" was implemented for r.in.xyz, I humbly think the approach there is pretty clean and useful.

Well, the manual does not really explain yet how to use that:
http://grass.osgeo.org/grass70/manuals/r.in.xyz.html

Please consider to add more.

thanks
Markus

> Besides filtering co-variant outliers, the use case there was to filter by z-range when building 3D slices as part of a raster3D import, when the import data value for the raster is not the "z" column; see the r3.in.xyz.py module for an example of how it is used. (unrelated, but I'd also note that the parallelization method for z-level slice import in r3.in.xyz works out to be surprisingly efficient)
>
>
> regards
>
> --
> Hamish <hamish.webmail at gmail.com>