clusterPower (version 0.6.111)

expit: The expit and logit functions

Description

The expit and logit functions are useful shortcuts when using logistic regression models.

Usage

expit(x)
logit(p)

Arguments

x

a real number

p

a number between 0 and 1, i.e. a probability

Value

A numeric value, possibly vectorized, depending on the input.

Details

The logit function is defined as logit(p) = log(p)/log(1-p) and can also be described as the log odds of a given probability. The expit is the inverse of the logit function and is defined as expit(x) = exp(x)/(1+exp(x)).

Examples

# NOT RUN {
 
expit(-2)
curve(expit(x), from=-5, to=5)

logit(.5)
curve(logit(x), from=0, to=1)
# }