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-------------------------------------------------------------------------------- There is no nesting here. It should suffice to cycle over the numerators and find the matching denominators, or vice versa. Here is one way: foreach num of var q*num { local den : subinstr local num "num" "den", all local stub : subinstr local num "num" "", all gen `stub' = `num' / `den' } Here is another way. This time we focus on getting the stubs by getting a varlist of all the numerators and zapping the text "num". unab nums : q*num local stubs : subinstr local nums "num" "", all foreach s in local stubs { gen `s' = `s'num/`s'den } As you can see, I don't trap any cases in which a numerator doesn't have a matching denominator, or indeed vice versa, but that could be done. Nick n.j.cox@durham.ac.uk --- On Tue, 4/27/10, Dr. Bill Westman <bigweb_ddt@yahoo.com> wrote: > From: Dr. Bill Westman <bigweb_ddt@yahoo.com> > Subject: st: possible nested loop with multiple items > To: statalist@hsphsun2.harvard.edu > Date: Tuesday, April 27, 2010, 5:12 PM > This is probably quite simple, but > I've tried and failed a few times to write a working loop. > > What I have isthe number of observations stored in > variables representing numerators and denominators of > several hundred questions. The list has matched > numerators and denominators, but each item has different > numbers of letters (e.g.q_01a and q_01b, but q_02a-c). > Also numbers skip. > > q_01a_num > q_01b_num > q_02a_num- > q_02x_num > q_02a_den > q_02b_den > q_02x_den > > I'd like to either loop through each item to > gen prop_`i' = q_***_num/q_***_den > > or contract (if that is easier). > > Any suggestions would be appreciated. > > Thanks! > > Bill > > > > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/statalist/faq > * http://www.ats.ucla.edu/stat/stata/ > * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/