Re: [GRASS-user] Using a polygon as a Mask
António Rocha wrote: > What I am affraid is that when I convert Vector to RASTER I will obtain > a mask that is not exacly the polygon in the boundaries of the polygon. > For instance, if a pixel is "cuttted" by the polygons boundaries is it > considered part odf the polygon or not? --%<--- Antonio, an idea: if you know the "real" scale of your vector map then you can decide (calculate) what the resolution of your raster map(s) would be. Then define your region with a higher resolution and expect to have a reliable conversion. Hope this is is correct and not misleading, Nikos ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Using a polygon as a Mask
Thank you Christian What I am affraid is that when I convert Vector to RASTER I will obtain a mask that is not exacly the polygon in the boundaries of the polygon. For instance, if a pixel is "cuttted" by the polygons boundaries is it considered part odf the polygon or not? Thanks Antonio Christian Schwartze wrote: There is no way to use a vector geometry in mapcalculator (or mapcalc) directly, hence, you have to convert it to raster before. Christian. -- From: "António Rocha" Sent: Thursday, May 27, 2010 2:08 PM To: "GRASS user list" Subject: [GRASS-user] Using a polygon as a Mask Greetings I have polygon that I want to use to define an for which I want to calculate some indicators (almost as a mask). Is it possible to use it directly in mapcalculator or do I have to convert it to RASTER and only then I can use it in mapcalculator as a mask? Thanks Best regards, Antonio __ Information from ESET NOD32 Antivirus, version of virus signature database 5149 (20100527) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user __ Information from ESET NOD32 Antivirus, version of virus signature database 5149 (20100527) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __ Information from ESET NOD32 Antivirus, version of virus signature database 5150 (20100527) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Using a polygon as a Mask
There is no way to use a vector geometry in mapcalculator (or mapcalc) directly, hence, you have to convert it to raster before. Christian. -- From: "António Rocha" Sent: Thursday, May 27, 2010 2:08 PM To: "GRASS user list" Subject: [GRASS-user] Using a polygon as a Mask Greetings I have polygon that I want to use to define an for which I want to calculate some indicators (almost as a mask). Is it possible to use it directly in mapcalculator or do I have to convert it to RASTER and only then I can use it in mapcalculator as a mask? Thanks Best regards, Antonio __ Information from ESET NOD32 Antivirus, version of virus signature database 5149 (20100527) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] Using a polygon as a Mask
Greetings I have polygon that I want to use to define an for which I want to calculate some indicators (almost as a mask). Is it possible to use it directly in mapcalculator or do I have to convert it to RASTER and only then I can use it in mapcalculator as a mask? Thanks Best regards, Antonio __ Information from ESET NOD32 Antivirus, version of virus signature database 5149 (20100527) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
