[R-sig-Geo] read function for LAS data

[Michael Sumner]

Thanks Howard, do you know of people working with LAS data in R, or
any efforts to link to liblas? I'd be keen to get involved eventually,
but it's not an area I have particular strengths. I've noticed the "R"
data format driver in GDAL (for reading/writing simple arrays in R's
save() format), so there must be some in that community using R in a
fairly intimate way.

BTW, I don't want this example to be seen as some kind of snub to the
efforts of projects like liblas, I'm really interested in the fact
that it *can* be done - not necessarily pushing that it should be
done. The impetus here was really my interest in alternative methods,
not just avoiding dependencies.

Tools like this can be helpful for basic data rescue when a full
solution is not at hand. There are endless varieties of raw binary
formats out there and very few have a commited team like liblas or
GDAL working to help.

Cheers, Mike.

On Tue, Jun 8, 2010 at 6:17 AM, Howard Butler <hobu.inc at gmail.com> wrote:
>
> On Jun 6, 2010, at 5:09 AM, Etienne Bellemare Racine wrote:
>
>> This is interesting, I'll try your code on my lidar files in the next few days.
>>
>> 2010-06-04 22:36, Michael Sumner wrote :
>>> Thanks Alex, I will eventually post this to a broader audience.
>>>
>>> I've used liblas and lastools, but the aim here is for a pure R
>>> implementation that is built directly from the LAS specification
>>> without 3rd party tools.
>>>
>>
>> What might be of interest in using liblas is that it provides support for many las versions and they plan to provide support for some versions to come (conditional to funding) so having an R binding might be of interest here. They are also working on the integration of a spatial index which would allow easier handling of large files. I must say I don't know how hard writing a wrapper for R might be for that particular tool.
>
> and controllable point caching, reprojection on the fly (when linked w/ GDAL), coordinate system description, and LAS 1.0-1.3 (no waveform for 1.3 though) support.  I would note that contrary to what the LAS specification says, there are many softwares out in the wild that don't write LAS files properly.  This causes big hassles, but it's libLAS' job to ensure that it can read everything, so we bend over backwards to ensure things work while doing our best to write valid files.
>
> I maintain an LAS sample library at http://liblas.org/samples .  They vary based on format types and the softwares that wrote them as this is what is most interesting to libLAS.  They are free for non-commercial usages.
>
> I understand the desire to not have external dependencies, which is the impetus for efforts like this.  It is unfortunate that distribution and platform issues make duplication of efforts like these economical in the short term.
>
> Howard
> _______________________________________________
> R-sig-Geo mailing list
> R-sig-Geo at stat.math.ethz.ch
> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>