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<p class="MsoNormal"><span style="color:#1F497D">Hello Even,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Since you helped me on GEOS compiling with GDAL, I think you may have ideas on what went wrong with my codes in the following. Could you tell me what you think on my segmentation fault error?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Thank you,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Limei<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Ran, Limei
<br>
<b>Sent:</b> Tuesday, December 18, 2012 3:21 PM<br>
<b>To:</b> gdal-dev@lists.osgeo.org<br>
<b>Subject:</b> point within polygon c++ API problem<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Hello,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I am working on a C++ codes which reads polygon from polygon shapefile to see whether a point is within a polygon. But, I got segmentation fault for pt.within (poGeometry). Could you tell me where I may have errors.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">1.<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>GDAL 1.9.1 is compiled with currect GEOS 3.3.6<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">2.<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>My c++ program compiled with GDAL.<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">3.<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]>Here are my codes:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">……<o:p></o:p></p>
<p class="MsoNormal"> float x = grid.x[col];<o:p></o:p></p>
<p class="MsoNormal"> float y = grid.y[row];<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal"> OGRPoint pt;<o:p></o:p></p>
<p class="MsoNormal"> pt.setX( x );<o:p></o:p></p>
<p class="MsoNormal"> pt.setY( y );<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> printf ("\tSet point\n");<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> OGRFeature *poFeature;<o:p></o:p></p>
<p class="MsoNormal"> poLayer->ResetReading();<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> while( (poFeature = poLayer->GetNextFeature()) != NULL )<o:p></o:p></p>
<p class="MsoNormal"> {<o:p></o:p></p>
<p class="MsoNormal"> OGRFeatureDefn *poFDefn = poLayer->GetLayerDefn();<o:p></o:p></p>
<p class="MsoNormal"> int iField;<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> OGRGeometry *poGeometry;<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> poGeometry = poFeature->GetGeometryRef();<o:p></o:p></p>
<p class="MsoNormal"> if( poGeometry != NULL && ( poGeometry->getGeometryType() ) == wkbPolygon )<o:p></o:p></p>
<p class="MsoNormal"> {<o:p></o:p></p>
<p class="MsoNormal"> printf ("\tGot polygon\n");<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> if ( pt.Within ( poGeometry ) )<o:p></o:p></p>
<p class="MsoNormal"> { //find the polygon where point is within and get item values<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> printf ("\tpoint in polygon\n");<o:p></o:p></p>
<p class="MsoNormal">………<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I got segmentation fault when processing gets: if ( pt.Within ( poGeometry ) )<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thank you,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Limei<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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