topic For the experts...how to quantify differences between layers?&nbsp; Please help! in ArcGIS Spatial Analyst Questions https://community.esri.com/t5/arcgis-spatial-analyst-questions/for-the-experts-how-to-quantify-differences/m-p/195330#M2771 <HTML><HEAD></HEAD><BODY><SPAN>Dear GIS Gurus, </SPAN><BR /><BR /><SPAN>If you could help here it would be immensely appreciated.&nbsp; Attached I have a simple JPG that clearly shows the problem I have.&nbsp; I basically have two soil layers (one looks like a grid, other shows actual contours) and I need to quantify the difference between the two layers.&nbsp;&nbsp; </SPAN><BR /><BR /><SPAN>I believe I know how to this quantitatively by area (i.e., how MUCH of each soil type is represented in each layer in each map), but what I </SPAN><SPAN style="font-style:italic;">really</SPAN><SPAN> need to do is quantify it SPATIALLY.&nbsp; In other words, to figure out not just how different the maps are in general, but to show specifically WHERE the differences are between them - likely requiring the production of a third map.&nbsp;&nbsp; Ideally I'd like to show directionality of differences (e.g., in these areas the soil category went up, in these areas it went down, in these areas the same, etc).&nbsp; </SPAN><BR /><BR /><SPAN>Does anyone know how to do any of these steps?&nbsp; Please help!&nbsp; And thanks so so much!</SPAN><BR /><BR /><SPAN>Jill&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 24/f/USA</SPAN></BODY></HTML> Wed, 13 Oct 2010 13:33:21 GMT JillFan 2010-10-13T13:33:21Z For the experts...how to quantify differences between layers?  Please help! https://community.esri.com/t5/arcgis-spatial-analyst-questions/for-the-experts-how-to-quantify-differences/m-p/195330#M2771 <HTML><HEAD></HEAD><BODY><SPAN>Dear GIS Gurus, </SPAN><BR /><BR /><SPAN>If you could help here it would be immensely appreciated.&nbsp; Attached I have a simple JPG that clearly shows the problem I have.&nbsp; I basically have two soil layers (one looks like a grid, other shows actual contours) and I need to quantify the difference between the two layers.&nbsp;&nbsp; </SPAN><BR /><BR /><SPAN>I believe I know how to this quantitatively by area (i.e., how MUCH of each soil type is represented in each layer in each map), but what I </SPAN><SPAN style="font-style:italic;">really</SPAN><SPAN> need to do is quantify it SPATIALLY.&nbsp; In other words, to figure out not just how different the maps are in general, but to show specifically WHERE the differences are between them - likely requiring the production of a third map.&nbsp;&nbsp; Ideally I'd like to show directionality of differences (e.g., in these areas the soil category went up, in these areas it went down, in these areas the same, etc).&nbsp; </SPAN><BR /><BR /><SPAN>Does anyone know how to do any of these steps?&nbsp; Please help!&nbsp; And thanks so so much!</SPAN><BR /><BR /><SPAN>Jill&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 24/f/USA</SPAN></BODY></HTML> Wed, 13 Oct 2010 13:33:21 GMT https://community.esri.com/t5/arcgis-spatial-analyst-questions/for-the-experts-how-to-quantify-differences/m-p/195330#M2771 JillFan 2010-10-13T13:33:21Z