On Wed, Apr 21, 2010 at 5:29 PM, Georg Kaspar <[email protected]> wrote: > hi, > > a quote from Markus' "Introduction to GRASS GIS Software" (1998): > > "[...] GRASS uses the "minimum distance to means" algorithm for deriving the > clusters [...]
This knowledge is essentially based on http://grass.osgeo.org/grass64/manuals/html64_user/i.cluster.html and "The GRASS 4 Image Processing manual" http://grass.itc.it/gdp/imagery/grass4_image_processing.pdf and http://trac.osgeo.org/grass/browser/grass/branches/releasebranch_6_4/imagery/i.cluster http://download.osgeo.org/grass/grass6_progman/c__exec_8c_source.html -> /* generate class means */ 00063 I_cluster_means(C); etc. > "minimum distance to means" is described in Lillesand and Kiefer (2000), as > a supervised classification technique which requires a priori information. > Does the i.cluster module use a modified version or have there been changes > since 1998? To my knowledge, no algorithm changes have been taken place. > the manual page does not contain any further information on how the module > works... Luckily it is open source :) > does anybody know which exact algorithm is used (k-means probably...)? I'm afraid that you need to compare it to a k-means algorithm. Please let us know your findings. Markus _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
