On Sun, Jun 14, 2009 at 7:26 PM, Nathan S. Watson-Haigh<nathan.watson-ha...@csiro.au> wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Dylan Beaudette wrote: >> On Sun, Jun 14, 2009 at 4:39 PM, Nathan S. >> Watson-Haigh<nathan.watson-ha...@csiro.au> wrote: >>> -----BEGIN PGP SIGNED MESSAGE----- >>> Hash: SHA1 >>> >>> Is there a library which is capable of identifying distinct clusters of >>> size n >>> from a series of XY coordinates? >>> >>> Failing this, I'd like to be able to to something like: >>> Using a sliding window of size n along the x-axis I'd like to determine the >>> distance between the center of the points in the window and the closest >>> point >>> outside the window. I could then use a distance cutoff to help define my >>> clusters of size n. However, how can I calculate this distance? >>> >>> Cheers, >>> Nathan >>> >> >> Here is a start, using PAM clustering: >> >> http://casoilresource.lawr.ucdavis.edu/drupal/node/340 >> >> cheers, >> Dylan >
Hi, > > Thanks, that looks interesting. However I need a clustering algorithm which > has > the following properties: > > 1) The ability to define clusters of size n > 2) No need to specify a priory how many clusters there will be > 3) The ability to omit data from any cluster. I don't think this package can > do > this. Time to do some reading on the various clustering algorithms, their assumptions, and their overall behaviour. Although I am not an expert, many of the constraints you are trying to impose on the clustering will require some kind of programming / decision on your end. It may help to re-formulate the problem into some kind of raster-operation, in which case GRASS GIS might be of interest to you. > I suspect for something like this I'll have to define, a priory, how tight > points within a cluster should be using some measure. > Hmm... In this case you may need to use a model-based / or density-based approach. See mclust and spatstat packages. (???) Cheers, Dylan > Any thoughts? > Nathan > > - -- > - -------------------------------------------------------- > Dr. Nathan S. Watson-Haigh > OCE Post Doctoral Fellow > CSIRO Livestock Industries > Queensland Bioscience Precinct > St Lucia, QLD 4067 > Australia > > Tel: +61 (0)7 3214 2922 > Fax: +61 (0)7 3214 2900 > Web: http://www.csiro.au/people/Nathan.Watson-Haigh.html > - -------------------------------------------------------- > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.9 (MingW32) > Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org > > iEYEARECAAYFAko1sWMACgkQ9gTv6QYzVL7grwCZAQh72v33vPNJJgEFJEhfyNc3 > 718AnA3k7wvvLEZ4NS1enW3Xp5WhO+qJ > =1gyG > -----END PGP SIGNATURE----- > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
