[R-sig-Geo] Need an algorithm to identify spatial

[Nicholas N Nagle]

Perhaps I am misunderstanding this, but it sounds like what you want to do is not what is typically called 'spatial clustering.'

If your data were in vector format (i.e. a polygon for each fire), what you might do is first merge (or aggregate) contiguous polygons and then simply count the number of burned polygons and find the areas of the polygons. I don't know how to merge polygons in Matlab or R but this a straightforward GIS operation.

If your data are a raster, then most GIS packages have a tool for converting raster data to vector data, and contiguous cells are automatically merged in this process.  In ArcGIS, this conversion tool might be in the Spatial Analyst Toolbox, but it's been awhile since I last checked.

So it sounds like what you want is not a clustering algorithm, but can be solved with basic GIS processing.

Nicholas



Nicholas N. Nagle, Assistant Professor
University of Colorado
Department of Geography
UCB 260, Guggenheim 110
Boulder, CO 80309-0260
phone: 303-492-4794