bayescount (version 0.9.99-9)

lnormal.params: Calculate the Log-Normal Mean and Standard Deviation Using the Normal Mean and Standard Deviation

Description

Function to calculate the equivalent values for the mean and standard deviation of a log-normal distribution from the mean and standard deviation of the normal distribution. Outputs from this function can be used with the dlnorm() function, and with the lognormal distribution in JAGS.

Usage

lnormal.params(mean, sd, coeff.variation)

Value

A list with elements representing the mean of the lognormal distribution, the standard deviation of the lognormal distribution, and the coefficient of variation.

Arguments

mean

either a single value or vector of values for the mean of the normal distribution.

sd

either a single value or vector of values for the standard deviation of the normal distribution. Ignored if values are supplied for coeff.variation.

coeff.variation

either a single value or vector of values for the coefficient of dispersion.

See Also

normal.params

Examples

mean <- 10
sd <- 2
lmean <- lnormal.params(mean,sd)[[1]]
lsd <- lnormal.params(mean,sd)[[2]]

curve(dnorm(x, mean, sd), from=0, to=20, col="blue")
curve(dlnorm(x, lmean, lsd), from=0, to=20, add=TRUE, col="red")