[R] L-BFGS-B needs finite values of 'fn'

[Jinsong Zhao]

Hi,

When I run the following code,

r <- c(3,4,4,3,5,4,5,9,8,11,12,13)
n <- rep(15,12)
x <- c(0, 1.1, 1.3, 2.0, 2.2, 2.8, 3.7, 3.9, 4.4, 4.8, 5.9, 6.8)
x <- log10(x)
fr <- function(c, alpha, beta) {
  P <- c + (1-c) * pnorm(alpha + beta * x)
  P <- pmax(pmin(P,1),0)
  -(sum(log(choose(n,r))) + sum(r * log(P)) + sum((n -r)* log(1-P)))
 }
fit <- mle((fr), start = list(c =0.2, alpha = 0, beta =0.1), method =
"L-BFGS-B")

I got:

Error in optim(start, f, method = method, hessian = TRUE, ...) :
  L-BFGS-B needs finite values of 'fn'

When I change "L-BFGS-B" to "BFGS" or anything else that optim()
support, there's no any error message.

What's wrong?

Any suggestions will be appreciated.

Jinsong