Thanks for the various solutions.<br><br>The points are about 5 million per tile, and there are 23 tiles (about 115 million total). I'm not sure if this is considered a large amount of mass input points.<br><br>Perhaps the table size is OK. I havent reached a size problem yet, but I was trying to avoided it from the start. Only using the xyz fields seems like a good solution, and bringing in the 4th column attribute after the fact, if it is even necessary.<br>
<br>Thanks much,<br>Mark<br><br><br><div class="gmail_quote">On Thu, Apr 10, 2008 at 2:39 AM, Hamish <<a href="mailto:hamish_b@yahoo.com">hamish_b@yahoo.com</a>> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div class="Ih2E3d">Mark wrote:<br>
> I have an ascii table of lidar data. The columns are x,y,z, and a<br>
> fourth column containing an integer code of some sort.<br>
<br>
</div>how many points are we talking about? millions? it the table becoming too<br>
huge?<br>
<br>
wc -l inputfile.txt<br>
<div class="Ih2E3d"><br>
<br>
> I have looked at the example in the man page about how to select<br>
> columns for importing via some shell manipulation of the input ascii<br>
> file, but I do not think it is applicable to what I'm doing (or perhaps<br>
> the caffeine boost is not in effect yet). I have also tried various<br>
> combinations of parameters in v.in.ascii.<br>
><br>
> I would like to import the XYZ to build the geometry for 3D points, and<br>
> have only "Cat" and "Code" in the attribute table. ("Code" being a<br>
> column name for the 4th column in the input ASCII). I cant seem to<br>
> find the combination of column definitions and other parameters to<br>
> achieve this. One option seems to import them all as "x double, y<br>
> double, z double, code int", and then after the import, drop the x,y,z<br>
> columns.<br>
<br>
</div>In GRASS 6.3: v.db.dropcol<br>
<br>
For GRASS 6.2.3 you can examine that script and do the SQLite trick by<br>
hand:<br>
<a href="http://trac.osgeo.org/grass/browser/grass/trunk/scripts/v.db.dropcol" target="_blank">http://trac.osgeo.org/grass/browser/grass/trunk/scripts/v.db.dropcol</a><br>
<div class="Ih2E3d"><br>
> Is it possible to put the first 3 ASCII column values to the geometry,<br>
> and use only the last column as an attribute?<br>
<br>
<br>
</div>another idea is to crop the file to only include the cat and code<br>
columns,<br>
cut -f1,4 -d',' inputfile.txt > outputfile.txt<br>
then use db.in.ogr (GRASS 6.3 only) to import the .csv file into SQLite,<br>
and then use v.db.connect to connect that database to your vector.<br>
(triple-check the cat+codes line up; is there a cat column or is that<br>
just sequential order? if so, use "seq" + "paste" to add that to the<br>
cut'ed code-only file)<br>
<br>
<br>
yet another idea is to do it like v.in.garmin/v.in.gpsbabel scripts, but<br>
that may be slow for many many points.<br>
<div><div></div><div class="Wj3C7c"><br>
<br>
> I'm using GRASS 6.2.3 and sqlite database.<br>
<br>
<br>
<br>
</div></div><font color="#888888">Hamish<br>
</font><div class="WgoR0d"><br>
<br>
__________________________________________________<br>
Do You Yahoo!?<br>
Tired of spam? Yahoo! Mail has the best spam protection around<br>
<a href="http://mail.yahoo.com" target="_blank">http://mail.yahoo.com</a><br>
<br>
</div></blockquote></div><br>