hyper.quality {BAT} | R Documentation |
Assess the quality of a functional hyperspace.
hyper.quality(distance, hyper)
distance |
A dist matrix representing the initial distances between species. |
hyper |
A matrix with trait data from function hyper.build. |
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.
A single value of quality.
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.
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)