BAT (version 2.9.6)

hyper.quality: Quality of hyperspace.

Description

Assess the quality of a functional hyperspace.

Usage

hyper.quality(distance, hyper)

Value

A single value of quality.

Arguments

distance

A dist object representing the initial distances between species.

hyper

A matrix with coordinates data from function hyper.build.

Details

This is used for any representation using hyperspaces, including convex hull and kernel-density hypervolumes. The algorithm calculates the inverse of the squared deviation between initial and euclidean distances (Maire et al. 2015) after standardization of all values between 0 and 1 for simplicity of interpretation. A value of 1 corresponds to maximum quality of the functional representation. A value of 0 corresponds to the expected value for an hyperspace where all distances between species are 1.

References

Maire et al. (2015) How many dimensions are needed to accurately assess functional diversity? A pragmatic approach for assessing the quality of functional spaces. Global Ecology and Biogeography, 24: 728:740.

Examples

trait = data.frame(body = c(1,2,3,4,4), beak = c(1,1,1,1,2))
distance = gower(trait)

hyper = hyper.build(trait, axes = 2)
hyper.quality(distance, hyper)

hyper = hyper.build(trait, axes = 0)
hyper.quality(distance, hyper)