DescTools (version 0.99.14)

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 $[-\infty, \infty ]$. It is defined as: $$y = log\left (\frac{p}{1-p} \right ) \;\;\; \; \textup{where} \; \;\; p=\frac{x-min}{max-min}$$ The generalized inverse logit function provides the inverse transformation: $$x = p' \cdot (max-min) + min \;\;\; \; \textup{where} \; \;\; p'=\frac{exp(y)}{1+exp(y)}$$

See Also

logit

Examples

Run this code
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)

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