aod (version 1.3.3)

link: Transformation from the Observation Scale to the Link Scale

Description

The function transforms a variable from the observation scale (probability or count) to the link scale.

Usage

link(x, type = c("cloglog", "log", "logit"))

Value

$logit(x)=log(x/(1-x))$

$cloglog(x)=log(-log(1-x))$

Arguments

x

A vector of real numbers.

type

A character string. Legal values are “cloglog”, “log” and “logit”.

See Also

invlink

Examples

  x <- seq(.001, .999, length = 100)
  plot(x, link(x, type = "logit"),
       type = "l", lwd = 2, ylab = "link(proba.)")
  lines(x, link(x, type = "cloglog"), lty = 2, lwd = 2)
  grid(col = "black")
  legend(0, 6, legend = c("logit(x)", "cloglog(x)"),
         lty = c(1, 2), bg = "white")