[GRASS-dev] Re: [GRASS-user] LiDAR LAS import

[Markus Metz]

Hamish wrote:
> Markus Metz wrote:
[snip]
>
>> v.in.lidar is a notch faster than las2txt | v.in.ascii. And
>> easier to use...
>
> I'm not too surprised the speed difference is not so huge, as
> unix pipes are very efficient. but the easier to use thing is
> very important.. both las2txt and v.in.ascii are a bundle of
> command line switches to get right.
>
>
>> Speed comparisons:
>>
>> # sample las file with 1,287,775 points
>>
>> # with table and topology
> ...
>> real    6m34.430s
> ...
>> real    6m13.823s
> ...
>> # without table, with topology
> ...
>> real    1m53.578s
> ...
>> real    1m44.876s
>
>
> I take it that without topology it runs in just seconds?

Update: no attribute table, no topology

time las2txt -i points.las --stdout --parse xyz --delimiter "|" |
v.in.ascii in=- out=points_ascii -ztb x=1 y=2 z=3

real	0m20.932s
user	0m18.424s
sys	0m6.869s


time v.in.lidar in=points.las out=points_las -obt

real	0m9.117s
user	0m2.946s
sys	0m5.985s


Markus M