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<div class="moz-cite-prefix">On 07/17/2018 12:09 AM, Rich Shepard
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:alpine.LNX.2.20.1807161407300.23050@salmo.appl-ecosys.com">On
Mon, 16 Jul 2018, Micha Silver wrote:
<br>
<br>
<blockquote type="cite">
<blockquote type="cite"> Current region rows: 47371, cols:
83934
<br>
</blockquote>
<br>
That means that each raster will have about 4 billion cells. A
raster with
<br>
integer values takes 32 bits per pixel, (double precision about
the same,
<br>
float about 1/2 of that), so if the whole raster needs to be
kept in
<br>
memory, you would require some 16GB of RAM....
<br>
</blockquote>
<br>
Micha,
<br>
<br>
So when creating vector contours grass7 needs to keep all raster
cells in
<br>
memory while it's processing.
<br>
<br>
</blockquote>
A single contour line could possibly begin at one side of the
raster, and end at the other side. So, without knowing any better, I
would guess that the whole raster needs to be kept in memory.<br>
<br>
<blockquote type="cite"
cite="mid:alpine.LNX.2.20.1807161407300.23050@salmo.appl-ecosys.com">
This suggests that the solution is to create a mask and generate
the
<br>
contours only within that area.
<br>
</blockquote>
or create a lower resolution version of the DEM, if you can live
with the reduced accuracy. <br>
<br>
<blockquote type="cite"
cite="mid:alpine.LNX.2.20.1807161407300.23050@salmo.appl-ecosys.com">
<br>
Thanks,
<br>
<br>
Rich
<br>
<br>
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<br>
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<br>
<a class="moz-txt-link-freetext" href="https://lists.osgeo.org/mailman/listinfo/grass-user">https://lists.osgeo.org/mailman/listinfo/grass-user</a><br>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
Micha Silver
Ben Gurion Univ.
Sde Boker, Remote Sensing Lab
cell: +972-523-665918</pre>
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