<div dir="ltr">thank you all for your suggestions.<div>Dear Nikos, I have some 0-1 rasters that represents presence-absence of different land covers. Each raster's resolution is 10x10m, thus i want to compute the sum in order to obtain the surface covered by each land cover within my buffers. As regards to the buffer, i want to use the 0-100, 0-200, 0-300, 0-400 and 0-500 for computing stats. I can do it separately with the module v.rast.stats. I just don't know how to loop it in a python script</div><div>Dear Stefan, thank you, i guess that using multiple rasters as input would be a good solution. however i would really like to loop it using a python script since that would be useful in other situation that i'm going to face in the next days</div><div>Dear Micha thank you, i'll try ASAP!</div></div><br><div class="gmail_quote"><div dir="ltr">Il giorno lun 29 ott 2018 alle ore 21:07 Micha Silver <<a href="mailto:tsvibar@gmail.com">tsvibar@gmail.com</a>> ha scritto:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div style="direction:ltr" bgcolor="#FFFFFF" text="#000000">
<p>Some further python specific tips that might help.</p>
<p><br>
</p>
<p>To get a list of rasters that match some pattern (say you have
many rasters like "band1", "band2",...), then run v.rast.stats on
each of them in a loop to get zonal stats in the vector "buffers":<br>
</p>
<p><br>
</p>
<p><font size="+1"><tt># This must be run from within a grass
session</tt><tt><br>
</tt></font></p>
<p><font size="+1"><tt>import grass.script as gscript</tt></font></p>
<p><font size="+1"><tt>rast_list = gscript.read_command("g.list",
type = "rast", pattern = "band*").strip().split("\n")</tt></font></p>
<p><font size="+1"><tt># Loop thru the rasters, run v.rast.stats,
and specify the column prefix using the raster name.</tt></font></p>
<p><font size="+1"><tt>methods = ("minimum", "maximum", "average",
"sum") # add whatever stats you need</tt><tt><br>
</tt></font></p>
<p><font size="+1"><tt>for r in rast_list:</tt><tt><br>
</tt></font></p>
<p><font size="+1"><tt> gscript.run_command("v.rast.stats", </tt></font></p>
<p><font size="+1"><tt> map_ = "buffers", raster=r,
column_prefix=r, method=methods)</tt></font></p>
<p><br>
</p>
<p><br>
</p>
<p>Be aware that if you have many rasters, you'll end up with
many,many columns in the "buffers" vector<br>
</p>
<p><br>
</p>
<p><br>
</p>
<div class="m_-3552665679187335822moz-cite-prefix">On 10/29/18 9:54 PM, Stefan Blumentrath
wrote:<br>
</div>
<blockquote type="cite">
<div class="m_-3552665679187335822WordSection1">
<p class="MsoNormal"><span>Hi
Alessandro,<u></u><u></u></span></p>
<p class="MsoNormal"><span><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">You could try v.rast.bufferstats [1], if you do
not have hundrets of thousands of points….<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">If the buffers don`t overlap, you could use
v.rast.stats [2] from the upcoming GRASS 7.6 release, that
will allow multiple raster input…<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">Otherwise have a look at the general
introduction to GRASS and Python [3].<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">Cheers<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">Stefan<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">1: <a href="https://grass.osgeo.org/grass74/manuals/addons/v.rast.bufferstats.html" target="_blank">
https://grass.osgeo.org/grass74/manuals/addons/v.rast.bufferstats.html</a><u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">2: <a href="https://grass.osgeo.org/grass76/manuals/v.rast.stats.html" target="_blank">
https://grass.osgeo.org/grass76/manuals/v.rast.stats.html</a><u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">3: <a href="https://grasswiki.osgeo.org/wiki/GRASS_and_Python" target="_blank">
https://grasswiki.osgeo.org/wiki/GRASS_and_Python</a><u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<p class="MsoNormal"><b><span lang="EN-US">From:</span></b><span lang="EN-US"> grass-user
<a class="m_-3552665679187335822moz-txt-link-rfc2396E" href="mailto:grass-user-bounces@lists.osgeo.org" target="_blank"><grass-user-bounces@lists.osgeo.org></a>
<b>On Behalf Of </b>Alessandro Sebastiani<br>
<b>Sent:</b> mandag 29. oktober 2018 16:06<br>
<b>To:</b> <a class="m_-3552665679187335822moz-txt-link-abbreviated" href="mailto:grass-user@lists.osgeo.org" target="_blank">grass-user@lists.osgeo.org</a><br>
<b>Subject:</b> [GRASS-user] zonal statistics for multiple
areas<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<div>
<p class="MsoNormal">Hello to everybody,<u></u><u></u></p>
<div>
<p class="MsoNormal">I hope my question is appropriate for
this mail list. I have created 5 different buffer layers
(d=100,200,300,400,500 m) from a point vector. Now i want
to compute some zonal statistics using different rasters
as input. I know how to do that separately, but i was
wondering how could i automate this procedure using a
python script. I know python's basics, but i was not able
to do so following guidelines that i found on the
internet, e.g GRASS tutorial. Thank you in advance, A<u></u><u></u></p>
</div>
</div>
</div>
<br>
<fieldset class="m_-3552665679187335822mimeAttachmentHeader"></fieldset>
<pre class="m_-3552665679187335822moz-quote-pre">_______________________________________________
grass-user mailing list
<a class="m_-3552665679187335822moz-txt-link-abbreviated" href="mailto:grass-user@lists.osgeo.org" target="_blank">grass-user@lists.osgeo.org</a>
<a class="m_-3552665679187335822moz-txt-link-freetext" href="https://lists.osgeo.org/mailman/listinfo/grass-user" target="_blank">https://lists.osgeo.org/mailman/listinfo/grass-user</a></pre>
</blockquote>
<pre class="m_-3552665679187335822moz-signature" cols="72">--
Micha Silver
Ben Gurion Univ.
Sde Boker, Remote Sensing Lab
cell: +972-523-665918</pre>
</div>
</blockquote></div>