Hello ADE gurus,
I am looking for a simple way to aggregate observation points for one
single species (of dragonflies in this particular case) spatially.
I have a simple file with <x;y> coordinates in Swiss projection units
(meric plan; e.g. <715000;215000>) and an identificator (point-id). What
I want is to aggregate all observation points of a species located at a
distance of each other shorter than say 200 m into a single cluster (and
simply associate with this cluster the presence of the species). The
datafile is relatively big (2955 points) and I have memory problems when
trying to use the 'dist' function in SPlus. Moreover, I want to keep the
geographic dimension into the analysis.
I tried several options of analyses (in ArcInfo and SPlus), but yet no
one was entirely successful. What I really need is an automatic
procedure that I could run successively and easily for many species.
Does anybody has a suggestion on how to do this with ADE (or SPlus) ?
Thanks a lot in anticipation
Antoine
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| |
| Antoine Guisan, Dr. Ecological Modeling & GIS |
| |
| Centre Suisse de Cartographie de la Faune (CSCF) |
| Terreaux 14 tel +41 32 724 92 97 |
| CH-2000 Neuch‰tel fax +41 32 717 79 69 |
| Suisse Antoine.Guisan@cscf.unine.ch |
| http://www.cscf.ch |
| |
| You can also send me a fax at my home office |
| fax +41 21 683 30 67 |
| |
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