program define _glmilnk         STB-16  sg16.3
    local eta `1'
    local mu  `2'
    local pow `3'
    local k   `4'
    cap gen `mu'=. /* in case it doesn't exist */
    if ("$S_E_link"=="pow") {
           if `pow'== 0 { replace `mu' = exp(`eta') }
           else { replace `mu' = `eta'^(1/`pow') }
           exit
    }
    if "$S_E_fam" == "bin"  {
           if "$S_E_link" == "l"  {
                replace `mu' = 1/(1+exp(-`eta'))
           }
           if "$S_E_link" == "p"  {
                replace `mu' = normprob(`eta')
           }
           if "$S_E_link" == "c"  {
                replace `mu' = 1-exp(-exp(`eta'))
           }
    }
    if "$S_E_fam" == "poi"  { replace `mu' = exp(`eta') }
    if "$S_E_fam" == "gam"  { replace `mu' = 1/`eta' }
    if "$S_E_fam" == "ivg" { replace `mu' = 1/sqrt(`eta') }
    if "$S_E_fam" == "nb" { replace `mu' = `k'/(exp(-`eta')-1) }   
    
end