R: Transformation from the Observation Scale to the Link Scale

link {aod} | R Documentation

## 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"))

### Arguments

`x` | A vector of real numbers.
`type` | A character string. Legal values are “cloglog”, “log” and “logit”.

### Value

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

### 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")

[Package aod version 1.3 Index]