Slope analysis produce NODATA at the edge

[MdOmerHossain]

Hi,

I was calculating slope by using Atan (rise/run) equation in radian. The calculated slope layer doesn't intersect with the water layer which I used for Euclidean distance (got the run). Though slope layer intersects with waterbody layer in some of the places but in most of the places there is gap of 1 cell. Why is this happening"? 

I have attached some screenshots. Blue layer is the waterbody layer. My cell size is 2.5ft. 2nd image is the zoom out image.

Thank you.

[DanPatterson]

You should look at the newer tools if you are running Pro 3.4

Surface Parameters (Spatial Analyst)—ArcGIS Pro | Documentation

How Slope works—ArcGIS Pro | Documentation

there is even a section on edge affects

Calculation methods and the edge effect

There is nothing "wrong" with what you are showing, it is the nature of how edges and calculations are dealt with.  If it really bothers you, buffer (Expand if using raster data) by 1 cell