*! Version 1.0.0   (STB-58: sxd2)
program define coding, eclass
	version 6.0
	local varlist "required existing"     
	local if "optional"
	local in "optional"
	parse "`*'"

   	if "$S_E_cmd"=="coding" {
     		error 301
	   }

*******get the dependent variable**************************
      local c=1
	local depvar " "
      local temp: word `c' of `varlist'
      local depvar `temp'

*******get the first stage covariates************	
        local c=2
	local first " "
	unabbrev `varlist'
	local n: word count `varlist'
	while `c'<=`n' {
	local temp: word `c' of `varlist'
	local first `first' `temp'
	local c=`c'+1
	}

*****determine the number of strata and second stage*******
*****sample size for each stratum**************************
	tempvar grp_z grp_yz nobs
	qui egen `grp_z'=group(`first')
	qui egen `grp_yz'=group(`depvar' `first') 
	qui egen `nobs' =count(`grp_z'), by(`grp_yz')
	
	preserve
	gen grp_z=`grp_z'
	gen grp_yz=`grp_yz'
	gen nobs=`nobs'
	di in white "============OUTPUT OF CODING FUNCTION============"
	collapse `varlist' grp_z (count) nobs, by (grp_yz)
	list, nodisplay nolabel noobs
	drop grp_z grp_yz nobs
	di in blue "for functions requiring first stage sample sizes/prevalences"
	di in blue "enter these in the order of grp_yz"
	di in white "============END OF CODING FUNCTION==============="
	restore,preserve
 
est local cmd "coding"
end