<div dir="ltr"> <i>Hello to all users of GRASS,</i><div><i><br></i></div><div style><i> I have LiDAR data in ASCII txt files with only X, Y and Z coordinates, which I want to import and create DEM models from in GRASS. I'm new to this kind of data processing.</i></div>
<div style><i> </i></div><div style><i> I'am using the following approach in a new MAPSET:</i></div><div style><br></div><div style> db.connect driver=sqlite database=$GISDBASE/$LOCATION_NAME/$MAPSET/sqlite.db</div>
<div style> v.in.ascii input=b29_3.txt output=b29_3 fs=space z=3<br></div><div style> g.region vect=b29_3 -p</div><div style> </div><div style><i># I tried few times at this point to interpolate the points with IDW using v.surf.idw. It stated that I have to show in which column of the attribute table are Z values in order to execute the command.</i></div>
<div style><i> At this point I don't have an attribute table yet created for the vector map b29_3...so I tried this one:</i></div><div style><br></div><div style> v.db.addtable map=b29_3@testMapset11 columns=cat integer, x double precision, y double precision, z double precision</div>
<div style><br></div><div style> #<i> ...and after that:</i></div><div style> </div><div style> v.to.db map=b29_3 option=coor columns=x, y, z</div><div style><i><br></i></div><div style><i># for to populate the database with and finally use v.surf.idw</i></div>
<div style><br></div><div style> <i>Is it my approach correct because it takes too much time (I mean few hours for only one txt file with 3 500 000 points) and it's very slow...and I'm really not sure how to proceed? And if no what is the correct one? </i></div>
<div style><i> </i></div><div style><i> I tried also to create an attribute table even with v.in.ascii when still importing the data, but I don't have attributes and it doesn't create tables only for X, Y and Z coordinates (I don't know why).</i></div>
<div style><i><br></i></div><div style><i> Any help will be highly appreciated! Thank you!</i></div><div style><i><br></i></div><div style><i><br></i></div><div style><i> Greetings,</i></div><div style><i><br></i></div>
<div style><i> Adrian Kirilov</i></div><div style><br></div><div style><br></div><div style><br></div><div style><br></div><div style><br></div></div>