qwraps2 (version 0.6.1)

logit: logit and inverse logit functions

Description

transform x either via the logit, or inverse logit.

Usage

logit(x)
invlogit(x)

Arguments

x

a numeric vector

Details

The logit and inverse logit functions are part of R via the logistic distribution functions in the stats package. Quoting from the documentation for the logistic distribution

"qlogis(p) is the same as the logit function, logit(p) = log(p/1-p), and plogis(x) has consequently been called the 'inverse logit'."

See the examples for benchmarking these functions. The logit and invlogit functions are faster than the qlogis and plogis functions.

See Also

qlogis

Examples

library(rbenchmark)

# compare logit to qlogis
p <- runif(1e5)
identical(logit(p), qlogis(p))

if (FALSE) {
rbenchmark::benchmark(logit(p), qlogis(p))
}

# compare invlogit to plogis
x <- runif(1e5, -1000, 1000)
identical(invlogit(x), plogis(x))

if (FALSE) {
rbenchmark::benchmark(invlogit(x), plogis(x))
}