transform x
either via the logit, or inverse logit.
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.
Examples
library(rbenchmark)
# compare logit to qlogis
p <- runif(1e5)
identical(logit(p), qlogis(p))
#> [1] TRUE
if (FALSE) { # \dontrun{
rbenchmark::benchmark(logit(p), qlogis(p))
} # }
# compare invlogit to plogis
x <- runif(1e5, -1000, 1000)
identical(invlogit(x), plogis(x))
#> [1] TRUE
if (FALSE) { # \dontrun{
rbenchmark::benchmark(invlogit(x), plogis(x))
} # }