# twCoefLogitnormCi: twCoefLogitnormCi In logitnorm: Functions for the Logitnormal Distribution

## Description

Calculates mu and sigma of the logitnormal distribution from lower and upper quantile, i.e. confidence interval.

## Usage

 ```1 2 3 4``` ```twCoefLogitnormCi(lower, upper, perc = 0.975, sigmaFac = qnorm(perc), isTransScale = FALSE) ```

## Arguments

 `lower` value at the lower quantile, i.e. practical minimum `upper` value at the upper quantile, i.e. practical maximum `perc` numeric vector: the probability for which the quantile was specified `sigmaFac` sigmaFac=2 is 95% sigmaFac=2.6 is 99% interval `isTransScale` if true lower and upper are already on logit scale

## Value

named numeric vector: mu and sigma parameter of the logitnormal distribution.

## Author(s)

Thomas Wutzler

`logitnorm`
 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22``` ```mu=2 sd=c(1,0.8) p=0.99 lower <- l <- qlogitnorm(1-p, mu, sd ) # p-confidence interval upper <- u <- qlogitnorm(p, mu, sd ) # p-confidence interval cf <- twCoefLogitnormCi(lower,upper) all.equal( cf[,"mu"] , c(mu,mu) ) all.equal( cf[,"sigma"] , sd ) ```