logitnorm (version 0.8.39)

twCoefLogitnormMLE: twCoefLogitnormMLE

Description

Estimating coefficients of logitnormal distribution from mode and upper quantile

Usage

twCoefLogitnormMLE(mle, quant, perc = 0.999)

Value

numeric matrix with columns c("mu","sigma")

rows correspond to rows in mle, quant, and perc

Arguments

mle

numeric vector: the mode of the density function

quant

numeric vector: the upper quantile value

perc

numeric vector: the probability for which the quantile was specified

Author

Thomas Wutzler

See Also

logitnorm

Examples

# estimate the parameters, with mode 0.7 and upper quantile 0.9
mode = 0.7; upper = 0.9
(theta <- twCoefLogitnormMLE(mode,upper))
x <- seq(0,1,length.out = 41)[-c(1,41)]	# plotting grid
px <- plogitnorm(x,mu = theta[1],sigma = theta[2])	#percentiles function
plot(px~x); abline(v = c(mode,upper),col = "gray"); abline(h = c(0.999),col = "gray")
dx <- dlogitnorm(x,mu = theta[1],sigma = theta[2])	#density function
plot(dx~x); abline(v = c(mode,upper),col = "gray")
# vectorized
(theta <- twCoefLogitnormMLE(mle = seq(0.4,0.8,by = 0.1),quant = upper))
# flat
(theta <- twCoefLogitnormMLEFlat(mode))