Preference of pseudospecies for one side of a division

The preference is (f2 - f1) / (f2 + f1), where f1 and f2 are the relative frequencies of the pseudospecies in the negative and the positive group. It ranges from -1 (only in the negative group) to 1.

Usage

tw_preference(y, positive)

Arguments

y

A binary matrix of stands by pseudospecies.

positive

A logical vector. TRUE: the stand is in the positive group.

Value

A numeric vector of the preference of each pseudospecies.

Examples

# \donttest{
data(dune, package = "vegan")
psp <- pseudospecies(dune)
pos <- tw_ra(psp)$sample > 0
summary(tw_preference(psp, pos))
#>    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
#> -1.0000 -1.0000 -0.3333 -0.2077  0.6364  1.0000 
# }