Many thanks for all the responses to my query regarding identifying simulated fire scars and computing their sizes. I received many helpful responses, and thankfully no unhelpful ones. It turns out that what I'm looking for is called a connected clusters algorithm, and is, as I suspected, well-known in percolation theory. Julian Burgos provided some code that will do what I need. My next decision will be whether to convert Julian's code to Matlab, or to convert my existing Matlab code to R. Again, my thanks to all! regards, Mark A.
Dr. Mark C. Andersen, Professor Department of Fish, Wildlife, and Conservation Ecology New Mexico State University Las Cruces, NM 88003 575-646-8034 fax: 575-646-1281 web: web.nmsu.edu/~manderse