Computes species*species nestedness matrix and number of nestings
(inclusions) from regions*species presence-absence matrix.
Usage
incmatrix(regmat)
Arguments
regmat
0-1-matrix. Columns are species, rows are regions.
Value
A list with components
m
0-1-matrix. m[i,j]=1 means that the occupied region of
species j is a subset (not equal) of the region of species i.
ninc
integer. Number of strict inclusions.
neq
integer. Number of region equalities between species (not
including equality between species i and i).
References
Hausdorf, B. and Hennig, C. (2003) Nestedness of nerth-west European
land snail ranges as a consequence of differential immigration from
Pleistocene glacial refuges. Oecologia 135, 102-109.