logit {rxode2}

logit and inverse logit (expit) functions

Description

logit and inverse logit (expit) functions

Usage

logit(x, low = 0, high = 1)

expit(alpha, low = 0, high = 1)

logitNormInfo(mean = 0, sd = 1, low = 0, high = 1, abs.tol = 1e-06, ...)

probitNormInfo(mean = 0, sd = 1, low = 0, high = 1, abs.tol = 1e-06, ...)

Arguments

x

Input value(s) in range [low,high] to translate -Inf to Inf

low

Lowest value in the range

high

Highest value in the range

alpha

Infinite value(s) to translate to range of [low, high]

mean

logit-scale mean

sd

logit-scale standard deviation

abs.tol

absolute accuracy requested.

...

other parameters passed to integrate()

Details

logit is given by:

logit(p) = -log(1/p-1)

where:

p = x-low/high-low

expit is given by:

expit(p, low, high) = (high-low)/(1+exp(-alpha)) + low

The logitNormInfo() gives the mean, variance and coefficient of variability on the untransformed scale.

Value

values from logit and expit

Examples

logit(0.25)

expit(-1.09)

logitNormInfo(logit(0.25), sd = 0.1)

logitNormInfo(logit(1, 0, 10), sd = 1, low = 0, high = 10)