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On 14/09/2010 02:08, Vishal Mehta wrote:
<blockquote
cite="mid:AANLkTingBnc0=cw4XN5J1jjhvGdQwF_7m5hCGjOw9QC=@mail.gmail.com"
type="cite">
<div class="gmail_quote">I have a bunch of rasters<br>
I want to extract average value each raster corresponding to vector
polygons<br>
<br>
Ideally, I would like to use v.what.rast BUT select only average (or a
small subset) of the different stats that it allows.<br>
</div>
</blockquote>
Just use v.rast.stats, then drop (or simply ignore) the columns you
don't need.<br>
I seem to remember someone mentioning on the list that the computing
time to get all of the stats is about the same as the time for just
one. So there's nothing to gain by computing only averages.<br>
<blockquote
cite="mid:AANLkTingBnc0=cw4XN5J1jjhvGdQwF_7m5hCGjOw9QC=@mail.gmail.com"
type="cite">
<div class="gmail_quote"><br>
Is that possible?<br>
<br>
The only other route I know in GRASS is:<br>
- r.average using the rasterized vector as base raster, followed by<br>
- v.what.rast to extract to points representing the centroid of the
polygons...<br>
<br>
The final route i know is<br>
- to export GRASS raster to multiband GTiff<br>
- then use starspan<br>
-however on that route I was not able to export multiple rasters to a
multiple-band GTiff....I would really like to know how to do that as
well..<br>
<br>
<br>
Thanks,<br>
Vishal<br clear="all">
<font color="#888888"><br>
-- <br>
Vishal K. Mehta, PhD<br>
Scientist<br>
Stockholm Environment Institute - US<br>
133 D St Suite F<br>
Davis CA 95616<br>
<a moz-do-not-send="true" href="http://www.sei-us.org" target="_blank">www.sei-us.org</a><br>
</font></div>
<br>
<br clear="all">
<br>
-- <br>
Vishal K. Mehta, PhD<br>
Scientist<br>
Stockholm Environment Institute - US<br>
133 D St Suite F<br>
Davis CA 95616<br>
<a moz-do-not-send="true" href="http://www.sei-us.org">www.sei-us.org</a><br>
<br>
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<br>
<br>
<pre class="moz-signature" cols="62">--
Micha Silver
<a class="moz-txt-link-freetext" href="http://www.surfaces.co.il/">http://www.surfaces.co.il/</a>
Arava Development Co. +972-52-3665918
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