DescTools (version 0.99.41)

Logit: Generalized Logit and Inverse Logit Function

Description

Compute generalized logit and generalized inverse logit functions.

Usage

Logit(x, min = 0, max = 1)
LogitInv(x, min = 0, max = 1)

Arguments

x

value(s) to be transformed

min

lower end of logit interval

max

upper end of logit interval

Value

Transformed value(s).

Details

The generalized logit function takes values on [min, max] and transforms them to span $[-\mathrm{\infty },\mathrm{\infty }]$. It is defined as:

$$y=log\left(\frac{p}{1-p}\right)\text{where}p=\frac{x-min}{max-min}$$

The generalized inverse logit function provides the inverse transformation:

$$x=p^{\prime }\cdot (max-min)+min\text{where}{p}^{\prime }=\frac{exp(y)}{1+exp(y)}$$

See Also

logit

Examples

# NOT RUN {
x <- seq(0,10, by=0.25)
xt <- Logit(x, min=0, max=10)
cbind(x,xt)

y <- LogitInv(xt, min=0, max=10)
cbind(x, xt, y)

# }