mcintosh_e {abdiv} | R Documentation |
McIntosh's evenness measure E
mcintosh_e(x)
x |
A numeric vector of species counts. |
For a vector x
of raw species counts, the McIntosh evenness measure
is
E = \frac{\sqrt{\sum_i x_i^2}}{\sqrt{(N - S + 1)^2 + S - 1},}
where N
is the total number of counts and S
is the total
number of species observed.
This index is appropriate only for raw counts, not transformed counts or proportions.
Equivalent to mcintosh_e()
in skbio.diversity.alpha
.
McIntosh's evenness measure, 0 < E \leq 1
. The index is
undefined when the total number of counts is 0, in which case we return
NaN
.
Heip C, Engels P. Comparing Species Diversity and Evenness Indices. J. Mar. Bioi. Ass. U.K. 1974;54:559-563.
x <- c(15, 6, 4, 0, 3, 0)
mcintosh_e(x)