[GRASS-user] Re: How to extract z-coordiante and write it into attribute table?

[Vincent Bain]

Tim,

Let's consider your source file is a simple x,y,z file (comma separated
values).
First run :
v.in.ascii input=/path/to/your/lidar/source/file output=lidar fs=, x=1
y=2 z=3

Your point cloud was imported in 3d vector mode but not yet connected to
an attribute table. Do this this way :
v.db.addtable map=lidar columns='cat integer,x double precision,y double
precision, z double precision'

To that point a table is connected to your vector and necessary fields
were added to the table. So you can upload x,y,z values to the table :
v.to.db map=lidar type=point option=coor columns=x,y,z

then drop x and y cols :
v.db.dropcol map=lidar column=x
v.db.dropcol map=lidar column=y

And you're done (hope so).

Good luck,
Vincent.