optim function argument missing

optimization, r

Solution

The problem is (straight from the optim help):

fn: A function to be minimized (or maximized), with first
argument the vector of parameters over which minimization is
to take place.

Your `kum.loglik` function needs to take a vector `v` which you pull the parameters out of, e.g.:

`kum.loglik=function(v) { a = v[1]; b = v[2]; ...}`

Problem

This is my code. The `kum.loglik` function returns negative loglikelihood and takes two arguments a and b. I need to find a and b that minimize this function using optim function. (n1,n2,n3 is pre-specified and passed to optim function. ``` kum.loglik = function(a, b, n1, n2, n3) { loglik = n1*log(b*beta(1+2/a,b)) + n2 * log(b*beta(1+2/a,b)-2*b*beta(1+1/a,b)+1) + n3 * log(b*beta(1+1/a,b)-b*beta(1+2/a,b)) return(-loglik) } optim(par=c(1,1), kum.loglik, method="L-BFGS-B", n1=n1, n2=n2, n3=n3, control=list(ndeps=c(5e-4,5e-4))) ``` This code should work well but it gives error message ``` Error in b * beta(1 + 2/a, b) : 'b' is missing ``` What is wrong in this code?

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