I am trying to fit a left-truncated gamma distribution in R. I have large claims above $25,000. Claims below $25,000 are unknown. I am trying to fit the gamma parameters through the MLE procedure in R. Could anyone suggest code for this? My current code is as follows:
Could someone please explain how to write code for this? I've made attempts with the fitdist function, but I am unsure what the truncated gamma function is named and what start it requires.
Failed Code:
dtruncated_gamma <- function(x, alpha, theta)
dtrunc(x, "gamma", shape=shape , scale=scale, a = 25000, b = Inf)
ptruncated_gamma <- function(x, alpha, theta)
ptrunc(x, "gamma", shape=shape , scale=scale, a = 25000, b = Inf)
fitdist(LargeClaims, "truncated_gamma", method = "mle", start = c(shape = 2, scale = 1000))
Thanks!
