https://community.esri.com/t5/arcgis-pro-questions/composing-raster-files-in-map-algebra/m-p/1058842#M41038 <P>Hello everyone, and thank you before hand for your help!</P><P>I am trying to calculate raster files in map algebra to compose a final map for the area and I have 4 different raster files (with the classification from 0 to 3) for land use, ex. roads, rivers, shoreline etc. When I sum the 4 rasters in map algebra I get as a result a raster file with 12 classes and not 4 (from 0 to 3) so they don't overlay.</P><P>How can I overcome this problem?&nbsp;</P><P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="MariaChamilaki_0-1621325034271.png" style="width: 400px;"><img src="https://community.esri.com/t5/image/serverpage/image-id/13492iB25A0167B6DC66EA/image-size/medium?v=v2&amp;px=400" role="button" title="MariaChamilaki_0-1621325034271.png" alt="MariaChamilaki_0-1621325034271.png" /></span></P><P>Of course I change the symbology within the final layer to have 4 classes but I am not sure this is the correct way to go...</P> Tue, 18 May 2021 08:06:10 GMT MariaChamilaki 2021-05-18T08:06:10Z https://community.esri.com/t5/arcgis-pro-questions/composing-raster-files-in-map-algebra/m-p/1058842#M41038 <P>Hello everyone, and thank you before hand for your help!</P><P>I am trying to calculate raster files in map algebra to compose a final map for the area and I have 4 different raster files (with the classification from 0 to 3) for land use, ex. roads, rivers, shoreline etc. When I sum the 4 rasters in map algebra I get as a result a raster file with 12 classes and not 4 (from 0 to 3) so they don't overlay.</P><P>How can I overcome this problem?&nbsp;</P><P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="MariaChamilaki_0-1621325034271.png" style="width: 400px;"><img src="https://community.esri.com/t5/image/serverpage/image-id/13492iB25A0167B6DC66EA/image-size/medium?v=v2&amp;px=400" role="button" title="MariaChamilaki_0-1621325034271.png" alt="MariaChamilaki_0-1621325034271.png" /></span></P><P>Of course I change the symbology within the final layer to have 4 classes but I am not sure this is the correct way to go...</P> Tue, 18 May 2021 08:06:10 GMT https://community.esri.com/t5/arcgis-pro-questions/composing-raster-files-in-map-algebra/m-p/1058842#M41038 MariaChamilaki 2021-05-18T08:06:10Z https://community.esri.com/t5/arcgis-pro-questions/composing-raster-files-in-map-algebra/m-p/1058847#M41039 <P>What are you trying to achieve?</P><P>A sum of different combination of weights will result in more number of classes. That's obvious.</P><P>Based on what criteria you want to define for your output map, you could do the calculation (sum) or use</P><P><A href="https://pro.arcgis.com/en/pro-app/latest/tool-reference/spatial-analyst/weighted-overlay.htm" target="_self">Weighted Overlay</A>&nbsp;</P><P><A href="https://pro.arcgis.com/en/pro-app/latest/tool-reference/spatial-analyst/weighted-sum.htm" target="_self">Weighted Sum</A>&nbsp;</P><P>If you feel the result is fine, and you need to further classify the results into fewer number of classes (in symbology), you could do so as well from Symbology pane.</P><P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="JayantaPoddar_0-1621330433903.png" style="width: 400px;"><img src="https://community.esri.com/t5/image/serverpage/image-id/13495i3D78394AC8429D7E/image-size/medium?v=v2&amp;px=400" role="button" title="JayantaPoddar_0-1621330433903.png" alt="JayantaPoddar_0-1621330433903.png" /></span></P><P>&nbsp;</P> Tue, 18 May 2021 09:34:32 GMT https://community.esri.com/t5/arcgis-pro-questions/composing-raster-files-in-map-algebra/m-p/1058847#M41039 JayantaPoddar 2021-05-18T09:34:32Z