Create species' values based on the species co-occurrence within focal ranges

Create single species' values based on the attributes of species co-occurring within individual ranges.

Usage

lets.field(x, y, z, weight = TRUE, xy = NULL, count = FALSE)

Arguments

x: A PresenceAbsence object or a presence-absence in matrix format (see xy argument for matrix use) with the species named in the columns.
y: Species attribute to be considered. It must be a numeric attribute.
z: Species names in the same order as the attributes and exactly the same as named in the matrix or in the PresenceAbsence object.
weight: If TRUE the value is weighted by species' range size, if FALSE the value is the mean of all species that co-occur within the focal species.
xy: If TRUE the presence-absence matrix contains the cell coordinates in the first two columns.
count: Logical, if TRUE a counting window will open.

Details

If the species do not co-occur with any other species NaN will be returned.

References

Villalobos, F. and Arita, H.T. 2010. The diversity field of New World leaf-nosed bats (Phyllostomidae). Global Ecology and Biogeography. 19, 200-211.

Villalobos, F., Rangel, T.F., and Diniz-Filho, J.A.F. 2013. Phylogenetic fields of species: cross-species patterns of phylogenetic structure and geographical coexistence. Proceedings of the Royal Society B. 280, 20122570.

Author

Bruno Vilela & Fabricio Villalobos

Examples

if (FALSE) {
data(PAM)
range <- lets.rangesize(x = PAM, units = "cell")
field <- lets.field(PAM, range, PAM$S, weight = TRUE)
}