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| From | James Bernard <jamesstatalist@gmail.com> |
| To | statalist@hsphsun2.harvard.edu |
| Subject | Re: st: indexing for first non-missing value |
| Date | Wed, 15 May 2013 20:13:55 +0800 |
Thanks Scott On Wed, May 15, 2013 at 7:52 PM, Scott Merryman <scott.merryman@gmail.com> wrote: > egen firstyear = min(year), by(id) > > Scott > > On Wed, May 15, 2013 at 6:46 AM, James Bernard <jamesstatalist@gmail.com> wrote: >> Hi all, >> >> I have been dealing with a dataset where I need to copy the value of >> the first non-missing value of one variable to create a new variable >> called first year observed: >> >> id year first year observed >> ------- ------------ >> ----------------------------- >> A . 1996 >> A 1996 1996 >> A 1997 1996 >> A 1998 1996 >> A . 1996 >> A . 1996 >> B 1998 1998 >> B 1999 1998 >> B . 1998 >> B . 1998 >> >> >> Going through Stata discussions, I found out that one way is to use indexing >> >> bysort id: gen first_year_observed=year[1] >> >> where the bracket indicates the first non-missing value >> >> But this find only the first value, be it missing or non-missing. Is >> there any simple indexing way? >> >> >> Thanks, >> James > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/faqs/resources/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/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/