*! version 1.0.0   01 September 1993   RG
program define fisher
    version 3.1
    local varlist "opt ex max(2)"
    local if "opt"
    local in "opt"
    parse "`*'"
*   parse "`varlist'", parse(" ")
    tempname rr
    cap confirm variable `2'
    if _rc!=0 {
         scalar `rr'=`1'
    }
    else {
         qui corr `1' `2' `if' `in'
         scalar `rr'=_result(4)
    }
    scalar Fisher=.5*ln((1+`rr')/(1-`rr'))
end