*! v 1.0.2 11Nov96. STB-34 sbe13
program define xri_nll /* normal likelihood */
        version 4.0
tempname ln2pi
scalar `ln2pi'=1.837877
local ll "`1'"
local M "`2'"
local S "`3'"

cap drop __U
quietly {
	if !$S_cv & !$S_lns {
		local s `S' /* sigma parametrization */
	}
	else {
		tempvar s
		if $S_lns { /* log S parametrization */
			if $S_cv { gen double `s' = `M'*exp(`S') }
			else gen double `s' = exp(`S')
		}
		else gen double `s' = `M'*`S'
	}

* s(igma) is scale factor

	gen double __U = ($S_mldepn-`M')/`s'
	replace `ll'=-0.5*`ln2pi'-log(`s')-0.5*__U^2
	if $S_trunc { replace `ll' = `ll'-log(1-normprob(-`M'/`s')) }
}
end