# Creating raster from grid algebra expression using point attribute values?

I have a point shapefile representing groundwater production wells with annual pumpage values distributed over a general area. I'd like to create a raster layer with each cell representing the potential production impact weighted by distance using the following expression:

``````outputraster = SUM n/i (Xi/log10(Di))
``````

Where 'Xi' is the annual production of well i and 'Di' is the distance in meters from well i.

Since there a multiple wells scattered over a wide area, the resulting raster cell values should be highest based on the density of wells in a given area, proximity to a given well, as well as the production value of a given well.

I've begun by creating a raster dataset, but am having trouble initiating the map algebra expression.

Can this calculation be performed within the raster calculator tool?

I have very little coding experience and my work with rasters extends only to interpolation and basic raster algebra expressions.

• Firstly use (Di+10). You need to produce separate raster for each well and use cell statistics. Small script / model can do it. – FelixIP Aug 9 at 20:39
• whats the `SUM n/i` bit mean? – Hornbydd Aug 9 at 22:58
• @FelixIP, what is the relevance of (Di+10)? – Devon Moore Aug 12 at 12:38
• @Hornbydd, it's supposed to represent the summation operator (using the Sigma symbol). – Devon Moore Aug 12 at 12:41
• To make it 1 at a point where distance equal 0 and log(0) doesn't exist – FelixIP Aug 12 at 19:32