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I'm attempting to create n sub-regions from a polygon based on a cluster analysis of a bunch of overlapping raster layers (physical layers, eg. depth, currents, waves...). Briefly, I can create a regular grid across the polygon, then extract physical attributes from the physical raster layers (eg. Gridspot or equivalent tool) then run a cluster analysis restricted to n number of clusters (In R or other Stats package). I can then identify each cluster-group, and plot them back in GIS (QGIS or ArcMap). I envisage however, that some cluster-groups will be dispersed (spatial outliers and not meaningful), whereas some will be clumped (worthy of being a sub-region). I could then manually draw around representative clumps to create n sub-regions.

Is there a tool like ArcMap 10.1 "Grouping Analysis" that can be run in QGIS? I'm only running 10.0.

Are there suggestions of a better way to do cluster analysis of multiple raster layers, to create n sub-regions (bio-regions)?

Thanks for your time...

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Not sure I'm understanding the role of the polygon. If you only have a single polygon, perhaps you can just clip the rasters as a pre-process and then run your cluster analysis directly on the rasters? Presuming you'll create a multi-dimensional raster/array as input, you should get an set of cluster ids back, you can visualize this (either by displaying the raster directly or converting back to a vector representation). –  Roland Sep 16 '13 at 21:07

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