program _tevaluator version 12.0 args lnf beta $sigma $t1 $g1 q tempvar x v m qui gen double `x' = $ML_y1 - (`beta') if "${arch}" != "0" | "${garch}" != "0"{ tempvar sigma qui gen double `sigma' = $insig^2 loc sigeq = "`a0'" local arch = $arch local garch = $garch loc max = `arch' if `garch' > `arch'{ local max = `garch' } forvalues i = 1/`arch'{ loc sigeq "`sigeq' + `a`i''*(`x'[_n-`i'])^2" } forvalues i = 1/`garch'{ loc sigeq "`sigeq' + `b`i''*`sigma'[_n-`i']" } qui replace `sigma' = `sigeq' if _n>`max' qui replace `sigma' = sqrt(abs(`sigma')) } qui replace `lnf' = lngamma(.5+`q') - ln(`sigma') -.5*ln(2) - .5*ln(_pi) - .5*ln(`q'-1) - lngamma(`q') - (.5 + `q')*ln((`x'^2)/(`sigma'^2 * 2 * (`q'-1)) + 1) end