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<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Hi Sotiris,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Thanks for your answer. The second workaround you propose should work, but is a bit complicated.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Does removal of islands with v.extract work for others? Am I doing something wrong?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Cheers<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Stefan
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext">From:</span></b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext"> S. Koukoulas (listes) [mailto:sotkouklistes@gmail.com]
<br>
<b>Sent:</b> 21. juni 2014 21:59<br>
<b>To:</b> Blumentrath, Stefan; grass-user@lists.osgeo.org<br>
<b>Subject:</b> Re: [GRASS-user] Remove islands with v.extract problem (again)<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom:12.0pt">I don't know how your file looks like, but one of the following should work,<br>
<br>
try <br>
v.clean and remove small areas<br>
or <br>
make the internal islands polygons, and using the same attributes (add them), use v.dissolve to get rid of internal polygons.<br>
<br>
regards,<br>
sotiris<o:p></o:p></p>
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<p class="MsoNormal">On 06/12/2014 12:35 PM, Blumentrath, Stefan wrote:<o:p></o:p></p>
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<p><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">Hi,<o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">I am trying to remove islands (here also in the topological sense) from a set of lake polygons.<o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">The polygon layer contains only the water bodies (means islands within the lakes have no category).<o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">I tryed v.extract -d as well as v.extract list/cats=1-99999999 both in GRASS 6 and 7 (on Ubuntu 12.04 LTS).<o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">In all tests the layer did not get modified as expected and islands were still present.<o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">This topic has been (repeatedly) discussed earlier. But the proposed solution (also in the manual of v.extract) did not work for others as well (quite some time ago):<o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""><a href="http://lists.osgeo.org/pipermail/grass-user/2006-January/032016.html">http://lists.osgeo.org/pipermail/grass-user/2006-January/032016.html</a><o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">I am wondering what the problem might be?<o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">Any idea? I can provide sample data if that might help...<o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">I am now using ST_ExteriorRing from PostGIS (<a href="http://postgis.net/docs/manual-2.1/ST_ExteriorRing.html">http://postgis.net/docs/manual-2.1/ST_ExteriorRing.html</a>) to achieve what I
want, but it would be nice to have a GRASS solution... <o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">Cheers<o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">Stefan<o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <o:p></o:p></span></p>
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<p class="MsoNormal"><br>
<br>
<br>
<o:p></o:p></p>
<pre>_______________________________________________<o:p></o:p></pre>
<pre>grass-user mailing list<o:p></o:p></pre>
<pre><a href="mailto:grass-user@lists.osgeo.org">grass-user@lists.osgeo.org</a><o:p></o:p></pre>
<pre><a href="http://lists.osgeo.org/mailman/listinfo/grass-user">http://lists.osgeo.org/mailman/listinfo/grass-user</a><o:p></o:p></pre>
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<p class="MsoNormal"><o:p> </o:p></p>
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