arcgis-desktopnodata
I'm doing urban change prediction in Land Change Modeler (TerrSet software), and i can't run Transition Sub-Model.
I don't know why, but I think it is because I have nodata value in Variable (slope image, elevation image, distance to roads) and I don't know how I can remove these values.
I tried in ArcGIS (reclass, copy raster).
Nodata value is -3,402823e+038
On second thought I decided to post my answer.
Normalising variables, which solved an issue is not exactly GIS thing, however careful spatial variables selection for regression analysis is.
I'd suggest caution with that many independent variables, because some of them aren't really independent, e.g. distance from 'river' and terrain slope.
I've made a quick check for terrain and 'rivers' shown below:
Random sampling (200 points) of Euclidian distance and slope shown no correlation between two. However when I reclassified distance into 5 classes and derived average slope per class result was very telling:
I also suggest to exclude precipitation from your analysis, unless it is a continental scale study. Even if it is, altitude will do better, because humans don't last long with a lack of oxygen
I was able to use mosaic to new raster. Problem was I needed to set it to "sum" instead of first. Finally, I got classes 1-8. The first time I still had some pixels as 0 and some now as 16.I guessed that some pixels in class 8 overlapped and their sum was 16. I carefully looked back through all the reclassified files. I found that I had used the same input with a value of 8 for two classes. I fixed this, and it solved both the 16 where pixels overlapped and the 0 pixels. In retrospect, using raster calculator "raste1" + "raster2" did work, but I had the same 16 and 0 pixels. If I have time this semester I will revisit con statements to try and make this workflow easier. I looked at it in help, but do not fully understand the syntax.
Best Answer
There is a useful method using
ConandIsNullstatements in the raster calculator to convert NoData to a different value.HowTo: Convert NoData values to other values for raster data