*! version 5.0 06Sep1999


* syntax is 
*
* . covar <varlist> [,] [list] [name(<matname>)]
*

program define covar
 version 5.0

 local if "optional"
 local in "optional"
 local varlist "required existing min(2)"
 local options "Name(string) List"
 parse "`*'"

 tempvar use
 quietly mark `use' `if' `in'
 quietly markout `use' `exog' `endog' `iv' `varlist' `fe'

 if "`name'" == "" { local name "COV" }

 tempname cov s
 matrix accum `cov' = `varlist', deviations noconstant
 scalar `s' = 1/_result(1)
 matrix `cov' = `s'*`cov'

 mat `name' = `cov'
 if "`list'" == "list" { mat list `name' }
end