I`m having problems using Raster Calculator to create a final cost raster. I have to add 7 raster data sets together and multiply each of them with the correct weight. The resulting raster is completely empty with unrealistic values of High:3,40282e+038 and Low:-3,40282e+038.

All the layers have the same cell size, same extent and no NoData. Any ideas what might be going wrong there?

  • Your Raster Calculator syntax would be helpful. We have no way of evaluating if the problem is syntax or software associated. – Jeffrey Evans Jan 23 '15 at 15:49
  • I doubt it has to do with the syntax but here it is: "slopes" * 0.05 + "soils" * 0.15 + "land_use" * 0.25 + "built_up" * 0.15 + "H_quarry" * 0.20 + "historical_sites" * 0.10 + "parks" * 0.10 – nimetu Jan 23 '15 at 21:39
  • Care multiplying by fraction (e.g. 0.05) generates a raster whose data type is float (i.e faction). So you need to have rasters (e.g. slopes,land_use,built_up etc) in fraction format (e.g. float) data types. – SIslam Jan 24 '15 at 5:26
  • Hi, thanks for your suggestion. I converted all the data to float format but output is exactly the same. – nimetu Jan 24 '15 at 13:13
  • I just tried to add the layers one by one and not all together at once. It actually works until I add the very last layer, and then again suddenly the same output and the same problem. – nimetu Jan 24 '15 at 13:33

I guess you are talking about ESRI ArcGIS rasters? It seems your rasters don't have proper statistics. Just try to apply a classified renderer in the symbology properties, you will be asked to create the statistics.

  • Yes, ESRI GRID rasters. I cant create statistics, get this error under Classify Renderer: "Unique histogram not available. You can import class breaks from another layer" and "Failed to initialize classify renderer (possibly too many unique values)". – nimetu Jan 23 '15 at 12:17
  • Can you create the histogram? – Pemburu Jan 23 '15 at 15:43
  • No, I cant create the histogram. – nimetu Jan 23 '15 at 21:28
  • All of the layers I am trying to combine are GRID except one in IMAGINE image format. It shouldn`t be a problem though. – nimetu Jan 23 '15 at 22:53

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