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Markus<br>
<br>
I tested the approach you proposed, but seems to be very slow for
large datasets: I am processing ~1000.000 points of observation on a
25m-Grid across Switzerland, where only few cells have multiple
points inside. While <i>v.to.rast</i> takes a few minutes for
conversion, the combination "<i>v.out.ascii input=pt output=-
column=VAL | r.in.xyz input=- z=4 output=pt method=sum</i>" has
been running for multiple hours and is still in progress. <br>
<br>
Is there any alternative to run this conversion? I need it to run
neighborhood analyses as kernel density with population field, i.e.
<i>r.neighbors in=pt out=pt_dens -c size=300 meth=sum</i>. Maybe
there is an approach to directly use the vector data and avoid
conversion- something as <i>v.neighbors meth=sum</i>? <br>
<br>
Thanks for you help,<br>
Patrick<br>
<br>
<br>
<div class="moz-cite-prefix">On 24.07.2015 04:13, Markus Neteler
wrote:<br>
</div>
<blockquote
cite="mid:CALFmHhu03+AQT-CxvmLZVjB0GFnjLJkJHem5H+NJ75yfaDFrxA@mail.gmail.com"
type="cite">
<pre wrap="">On Thu, Jul 23, 2015 at 11:00 AM, patrick s. <a class="moz-txt-link-rfc2396E" href="mailto:patrick_gis@gmx.net"><patrick_gis@gmx.net></a> wrote:
</pre>
<blockquote type="cite">
<pre wrap="">Dear all
I am puzzled on the behavior of v.to.rast. When several points fall into one
gridcell, the raster seems to get one value but not the sum of these. Is
there a way to sum these up instead?
</pre>
</blockquote>
<pre wrap="">
Yes. I have added a related example here:
<a class="moz-txt-link-freetext" href="http://grass.osgeo.org/grass70/manuals/v.to.rast.html#convert-vector-points-to-raster-with-raster-cell-binning">http://grass.osgeo.org/grass70/manuals/v.to.rast.html#convert-vector-points-to-raster-with-raster-cell-binning</a>
(while it does not really fit to that manual page it is expected
there. Perhaps we need to really enhance v.to.rast to do such a job
right away).
HTH
Markus
</pre>
</blockquote>
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