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title: >R: Biogeo
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What does BIOGEO do ?
Program BIOGEO computes a hierarchical agglomerative
proportional-link linkage clustering with constraint of spatial
contiguity, as proposed by
Legendre & Legendre (1984b), and
presents the results as a series of maps, one for each clustering
level. Since the clustering is computed from a similarity matrix, which
is of multivariate origin in most instances, then this method may be
considered as a form of multivariate mapping.
This agglomerative clustering uses a proportional-link linkage
algorithm; another program of this package,
K-MEANS, allows to compute
a non-hierarchical space-constrained clustering. The connectedness of
the clustering algorithm is determined by the user, between 0 (for
single linkage) and 1 (for complete linkage).
Legendre (1987)
has shown that the results of constrained clustering are fairly stable through a
wide range of values of connectedness.
In the Macintosh version, the program is limited to a maximum of 150
simultaneous groups at any one clustering level. Problems larger than
1000 localities have been analyzed using this program; it may become
necessary in such cases to request more core memory than attributed to
users by default.
Last updated on Saturday, March 30, 2013 by Philippe Casgrain