Nick Cox
>
> =========== begin ppa.ado
> program def ppa, rclass
> version 7
> syntax varlist(numeric min=2 max=2) [if] [in]
> marksample touse
> tokenize `varlist'
> args o1 o2
> qui count if ((`o1' > 0) | (`o2' > 0)) & `touse'
> local denom = r(N)
> qui count if (`o1' > 0) & (`o2' > 0) & `touse'
> local ppa = r(N) / `denom'
> di
> di as text "Chamberlain's PPA measure " _c
> di as res %5.4f `ppa' " (" %5.2f 100 * `ppa' " %)"
> end
> ============== end ppa.ado
>
> Syntax: ppa obs1 obs2 [if] [in]
This lacks a line at the end
before the -end- statement
return local ppa = `ppa'
Nick
[email protected]
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