Hi,
I would like to write a function that finds parameters of a log-normal
distribution with a 1-alpha CI of (x_lcl, x_ucl):
However, I don't know how to optimize for the two unknown parameters.
Here is my unsuccessful attempt to find a lognormal distribution with
a 90%CI of 1,20:
prior <- function(x_lcl, x_ucl, alpha, mean, var) {
a <- (plnorm(x_lcl, mean, var) - (alpha/2))^2
b <- (plnorm(x_ucl, mean, var) - (1-alpha/2))^2
return(a+b)
}
optimize(fn=prior, interval = c(-5, 100), 1, 20)
I understand that this problem has a closed form solution, but I would
like to make this a general function.
Thanks,
David
--
David LeBauer, PhD
Energy Biosciences Institute
University of Illinois Urbana-Champaign
1206 W. Gregory Drive
Urbana, IL 61801, U.S.A.
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