topic Re: IDW with a clipped geometry in ArcGIS Spatial Analyst Questions https://community.esri.com/t5/arcgis-spatial-analyst-questions/idw-with-a-clipped-geometry/m-p/512491#M7351 <HTML><HEAD></HEAD><BODY><BLOCKQUOTE class="jive-quote">Hi,<BR />I tried the input barrier polyline option by converting the polygons to polylines but this didn't work and still interpolated outside the polylines.<BR /></BLOCKQUOTE><BR /><SPAN> The barrier option in IDW uses a "line of sight" technique to determine which points are used when making a prediction at a location. Therefore, for example, if you have high values to the left of a barrier and low values to the right then your output will have a clear "split".</SPAN><BR /><BR /><SPAN>The mask option that is suggested by m.gasior clips the output after all the interpolation has been done.</SPAN><BR /><BR /><SPAN>You have to decide what you want, viz.,</SPAN><BR /><SPAN>- predictions should be influenced by the barrier, then use the barrier option</SPAN><BR /><SPAN>- clip the output after interpolation is done then use the mask environment option.</SPAN><BR /><BR /><SPAN>Hope this helps</SPAN><BR /><SPAN>Steve</SPAN></BODY></HTML> Wed, 07 Nov 2012 10:44:13 GMT SteveLynch 2012-11-07T10:44:13Z IDW with a clipped geometry https://community.esri.com/t5/arcgis-spatial-analyst-questions/idw-with-a-clipped-geometry/m-p/512489#M7349 <HTML><HEAD></HEAD><BODY><SPAN>Hi,</SPAN><BR /><SPAN>Can anyone tell me is there a way to use IDW with a clipped geometry.</SPAN><BR /><SPAN>I have 10 polygons with points inside them. I only want the interpolation to run within the polygons as they are not related to each other.</SPAN><BR /><SPAN>I tried the input barrier polyline option by converting the polygons to polylines but this didn't work and still interpolated outside the polylines.</SPAN><BR /><BR /><SPAN>Any help much appreciated.</SPAN><BR /><SPAN>Regards</SPAN><BR /><SPAN>Rachel</SPAN></BODY></HTML> Wed, 07 Nov 2012 08:38:09 GMT https://community.esri.com/t5/arcgis-spatial-analyst-questions/idw-with-a-clipped-geometry/m-p/512489#M7349 RachelS 2012-11-07T08:38:09Z Re: IDW with a clipped geometry https://community.esri.com/t5/arcgis-spatial-analyst-questions/idw-with-a-clipped-geometry/m-p/512490#M7350 <HTML><HEAD></HEAD><BODY><SPAN>You can try using raster analysis mask:</SPAN><BR /><BR /><SPAN>- In IDW tool dialog window click Environments</SPAN><BR /><SPAN>- In Raster Analysis section select your polygon layer as Mask</SPAN></BODY></HTML> Wed, 07 Nov 2012 08:54:15 GMT https://community.esri.com/t5/arcgis-spatial-analyst-questions/idw-with-a-clipped-geometry/m-p/512490#M7350 MarcinGasior 2012-11-07T08:54:15Z Re: IDW with a clipped geometry https://community.esri.com/t5/arcgis-spatial-analyst-questions/idw-with-a-clipped-geometry/m-p/512491#M7351 <HTML><HEAD></HEAD><BODY><BLOCKQUOTE class="jive-quote">Hi,<BR />I tried the input barrier polyline option by converting the polygons to polylines but this didn't work and still interpolated outside the polylines.<BR /></BLOCKQUOTE><BR /><SPAN> The barrier option in IDW uses a "line of sight" technique to determine which points are used when making a prediction at a location. Therefore, for example, if you have high values to the left of a barrier and low values to the right then your output will have a clear "split".</SPAN><BR /><BR /><SPAN>The mask option that is suggested by m.gasior clips the output after all the interpolation has been done.</SPAN><BR /><BR /><SPAN>You have to decide what you want, viz.,</SPAN><BR /><SPAN>- predictions should be influenced by the barrier, then use the barrier option</SPAN><BR /><SPAN>- clip the output after interpolation is done then use the mask environment option.</SPAN><BR /><BR /><SPAN>Hope this helps</SPAN><BR /><SPAN>Steve</SPAN></BODY></HTML> Wed, 07 Nov 2012 10:44:13 GMT https://community.esri.com/t5/arcgis-spatial-analyst-questions/idw-with-a-clipped-geometry/m-p/512491#M7351 SteveLynch 2012-11-07T10:44:13Z Re: IDW with a clipped geometry https://community.esri.com/t5/arcgis-spatial-analyst-questions/idw-with-a-clipped-geometry/m-p/512492#M7352 <HTML><HEAD></HEAD><BODY><SPAN>Thanks for you replies,</SPAN><BR /><SPAN>It looks like I'll use the polyline barrier as I want adjustments made before the interpolation rather than after with the mask.</SPAN><BR /><SPAN>Many thanks</SPAN><BR /><SPAN>Rachel</SPAN></BODY></HTML> Thu, 08 Nov 2012 09:33:51 GMT https://community.esri.com/t5/arcgis-spatial-analyst-questions/idw-with-a-clipped-geometry/m-p/512492#M7352 RachelS 2012-11-08T09:33:51Z Re: IDW with a clipped geometry https://community.esri.com/t5/arcgis-spatial-analyst-questions/idw-with-a-clipped-geometry/m-p/512493#M7353 <HTML><HEAD></HEAD><BODY><SPAN>Rachel</SPAN><BR /><BR /><SPAN>If you also have Geostatistical Analyst and ArcGIS10+ I would suggest that you try </SPAN><A href="http://resources.arcgis.com/en/help/main/10.1/index.html#//003000000008000000">Kernel Interpolation With Barriers</A><BR /><BR /><SPAN>The advantages include; optional standard error of prediction output and it does not use "line of sight" but rather "shortest distance around the barrier".</SPAN><BR /><BR /><SPAN>REgards</SPAN><BR /><SPAN>Steve</SPAN></BODY></HTML> Thu, 08 Nov 2012 14:32:20 GMT https://community.esri.com/t5/arcgis-spatial-analyst-questions/idw-with-a-clipped-geometry/m-p/512493#M7353 SteveLynch 2012-11-08T14:32:20Z