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From | Maarten Buis <maartenlbuis@gmail.com> |
To | statalist@hsphsun2.harvard.edu |
Subject | Re: st: Selecting maximum values and generating sum variable |
Date | Tue, 24 May 2011 09:12:21 +0200 |
On Tue, May 24, 2011 at 4:33 AM, Catherine Tisch wrote: > 1. We want to select the highest UVI value per ID per day from five > hourly measurements. It is possible for measurements to be zero and in > some instances data is missing. <snip> > 2. We want to know the sum of count of days per ID if UVIPeak is > not missing. *------------------ begin example --------------- clear input /// ID Day Hour UVI 1 1 11 5 1 1 12 9 1 1 13 7 1 1 14 3 1 1 15 4 1 2 11 7 1 2 12 8 1 2 13 2 1 2 14 1 1 2 15 . 1 3 11 1 1 3 12 2 1 3 13 1 1 3 14 1 1 3 15 0 2 1 11 . 2 1 12 . 2 1 13 . 2 1 14 . 2 1 15 . 2 2 11 9 2 2 12 10 2 2 13 10 2 2 14 8 2 2 15 6 end bys ID Day : egen UVIpeak = max(UVI) list bys ID Day : gen byte notmiss = !missing(UVIpeak) if _n == 1 bys ID : egen SumDays = total(notmis) list drop notmiss list *----------------------- end example ----------------------- (For more on examples I sent to the Statalist see: http://www.maartenbuis.nl/example_faq ) Hope this helps, Maarten -------------------------- Maarten L. Buis Institut fuer Soziologie Universitaet Tuebingen Wilhelmstrasse 36 72074 Tuebingen Germany http://www.maartenbuis.nl -------------------------- * * 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/