# Calculating Geometric Mean in Raster calculator

I am calculating Geometric Mean for land degradation mapping. I am applying following formula in ArcGIS 10.2- `("GW.img" * "LULC.img" * "Rain.img" * "Temp.img" * "Wind.img" * "NDVI.img" * "Livestock.img" * "Pop_Density.img" * "USLE" * "WEQ.img") ** (1/10.)` on the raster calculator. The final result is ranging from 4.1 to 8.5. But this map having various blank patches with no value. I am quite dubious about the way i am applying formula in raster calculator. Please, suggest me the right way to do it.

• Which software are you using? – ArMoraer Mar 13 '16 at 9:11
• ArcGIS 10.2 – prash_geo87 Mar 13 '16 at 9:15
• What error are you getting? – alphabetasoup Mar 13 '16 at 9:44
• In a repeated attempt, Now I got a final map, which result is ranging from 4.1 to 8.5. But this map having various blank patches with no value. I am quite dubious about formula which I have used for Geometric mean calculation. – prash_geo87 Mar 13 '16 at 10:59
• If you are dubious about the formula then where did it come from? – PolyGeo Mar 13 '16 at 11:43

My guess is that you have `NoData` or `Null` values in one or more of your input rasters.
As described in the Esri help page NoData and how it affects analysis, the presence of a `NoData` value in any of the input rasters can result in `NoData` in the output raster for some operators. This is definitely the case for the multiply/times map algebra operator, as shown below:
If my hunch is right, you will want to use the `con()` and `isnull()` map algebra operators to properly fill in the `NoData` values, as described in this GIS.SE question: Dealing with NoData in ArcGIS Spatial Analyst?.