hull.contribution {BAT}

Contribution of each observation to a convex hull hypervolume.

Description

Contribution of each species or individual to the total volume of one or more convex hulls.

Usage

hull.contribution(comm, relative = FALSE)

Arguments

comm

A 'convhulln' object or list, preferably built with function hull.build.

relative

A boolean (T/F) indicating whether contribution should be relative to total PD or FD (proportional contribution per individual or species). If FALSE, the sum of contributions for each site is equal to total PD/FD, if TRUE it is 1.

Details

The contribution of each observation (species or individual) to the total volume of a convex hull, calculated as the difference in volume between the total convex hull and a second hypervolume lacking this specific observation (i.e., leave-one-out approach; Mammola & Cardoso, 2020).

Value

A vector or matrix with the contribution values of each species or individual for each site.

References

Mammola, S. & Cardoso, P. (2020) Functional diversity metrics using kernel density n-dimensional hypervolumes. Methods in Ecology and Evolution. https://doi.org/10.1111/2041-210X.13424

Examples

comm = rbind(c(1,3,0,5,3), c(3,2,5,1,0))
colnames(comm) = c("SpA", "SpB", "SpC", "SpD", "SpE")
rownames(comm) = c("Site 1", "Site 2")

trait = data.frame(body = c(1,2,3,4,4), beak = c(1,5,4,1,2))
rownames(trait) = colnames(comm)

hv = hull.build(comm[1,], trait)
hull.contribution(hv)
hvlist = hull.build(comm, trait, axes = 2)
hull.contribution(hvlist, relative = TRUE)