On 12/02/08 03:43, Dylan Beaudette wrote:
On Monday 11 February 2008, Moritz Lennert wrote:Hello,I've finally gotten around to continue working on the d.thematic.* modules, and more specifically on the classification code. As mentioned earlier, I think it makes sense to make the latter into a library, so I decided to create lib_arraystats which contains functions for collecting basic statistics and for finding class breaks in arrays of doubles. In the future this could be filled with more statistical functions on such arrays. Could the gurus please have a look and tell me if the attached files are decent enough (except for the lacking documentation) to be committed to svn for further development ? Once that's done, I can also commit the d.thematic.area and v.class modules. MoritzNice work Moritz.On this thread-- it would be neat if we can use (along side Moritz's and existinf stat libs) the shared R library, when available. I think that it would have to be a compile-time option, and the user would have to have R installed, and compiled with the '--enable-R-shlib' flag. This would allow us to switch between the default, basic set of algorithms, and the entire suite of R codes. Some of these functions might not work with huge datasets (R works with data in-memory)-- but it would allow us to program more complicated algorithms without re-inventing them.
I agree that having a more direct link to R would be nice. At the same, I'm not sure if we should do this across all modules using stats. Maybe a g.rstats or v.rstats could be an option ?
This thread reminded me of doing this, as sometimes it is useful to look for "natural classes" within data. Instead of re-implementing a variation of K-means, we could just pass an array to the appropriate (set of) R functions.
I've done this, but via the plr interface between R and PostgreSQL. See attached script for an example.
Moritz
indics.sh
Description: application/shellscript
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