topic Can someone explain the slope calculation algorithm? in ArcObjects SDK Questions https://community.esri.com/t5/arcobjects-sdk-questions/can-someone-explain-the-slope-calculation/m-p/52960#M1402 <HTML><HEAD></HEAD><BODY><P>In the big picture my plan is to use ArcObjects to rewire the hillshade algorithm to ignore certain areas in a project I'm working on that relies heavily (almost entirely) on elevation data.&nbsp; Hillshade is calculated from a few different variables but the one I'm stuck on right now is slope.&nbsp; The same goes for the regular slope calculation tool so let's just talk about that to keep things simple-ish.</P><P></P><P>ArcGIS says that they calculate slope as follows:<IMG alt="ArcGIS explanation of slope calculation algorithm" class="jive-emoji image-1 jive-image j-img-original" src="/legacyfs/online/459376_slope explanation.PNG" /></P><P>But my concern is the fact that I cannot for the life of my understand why this formula works!&nbsp; Why are the cells adjacent to "e" multiplied by 2?&nbsp; Why is everything divided by 8? Is it like an averaging thing or something?&nbsp; Why on earth does the cell size matter? Is that related to Z-factor (another things I barely understand).</P><P></P><P>If someone could shed some light on what the heck is going on here I would greatly appreciate that.</P><P></P><P>Thanks,</P><P></P><P>Miles</P></BODY></HTML> Thu, 12 Sep 2019 19:16:49 GMT mileszoltak 2019-09-12T19:16:49Z Can someone explain the slope calculation algorithm? https://community.esri.com/t5/arcobjects-sdk-questions/can-someone-explain-the-slope-calculation/m-p/52960#M1402 <HTML><HEAD></HEAD><BODY><P>In the big picture my plan is to use ArcObjects to rewire the hillshade algorithm to ignore certain areas in a project I'm working on that relies heavily (almost entirely) on elevation data.&nbsp; Hillshade is calculated from a few different variables but the one I'm stuck on right now is slope.&nbsp; The same goes for the regular slope calculation tool so let's just talk about that to keep things simple-ish.</P><P></P><P>ArcGIS says that they calculate slope as follows:<IMG alt="ArcGIS explanation of slope calculation algorithm" class="jive-emoji image-1 jive-image j-img-original" src="/legacyfs/online/459376_slope explanation.PNG" /></P><P>But my concern is the fact that I cannot for the life of my understand why this formula works!&nbsp; Why are the cells adjacent to "e" multiplied by 2?&nbsp; Why is everything divided by 8? Is it like an averaging thing or something?&nbsp; Why on earth does the cell size matter? Is that related to Z-factor (another things I barely understand).</P><P></P><P>If someone could shed some light on what the heck is going on here I would greatly appreciate that.</P><P></P><P>Thanks,</P><P></P><P>Miles</P></BODY></HTML> Thu, 12 Sep 2019 19:16:49 GMT https://community.esri.com/t5/arcobjects-sdk-questions/can-someone-explain-the-slope-calculation/m-p/52960#M1402 mileszoltak 2019-09-12T19:16:49Z