*! version 3.1.0  02/08/94              (STB-19: ssa3)
program define asurvcrv
	version 3.0
	local options /*
*/ "WIth(string) BY(string)"
	local varlist "req ex min(2) max(2)"
	local if "opt"
	local in "opt"
	local weight "iweight aweight fweight"
	parse "`*'"
	parse "`varlist'", parse(" ")
	local time "`1'"
	local died "`2'"
	tempvar ratio dd
	if ("`died'"=="") {
		tempvar dd
		local died `dd'
		gen byte `dd' = 1
	}
	qui tab(`by') , gen(__g)
	qui cox `time' `with' __g* `if' `in' [`weight'`exp'], dead(`died')
	drop __g*
	parse "`with'", parse(" ")
	qui gen `ratio' = 1
	while ("`1'"!="") {
		qui summ `1' [`weight'`exp']
		qui replace `ratio' = `ratio'/exp(_b[`1']*(`1'-_result(3)))
		mac shift
	}
	_wsrvcrv `time' `died' `if' `in' [iw=`ratio'], by(`by')
end