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From |
Nick Cox <njcoxstata@gmail.com> |

To |
"statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu> |

Subject |
Re: st: Count the number of changing string values |

Date |
Fri, 14 Jun 2013 13:21:11 +0100 |

Fine. If we tsset id year and guess at labels 1 No 2 Yes then Yes after No the previous year is gen NY = drug == 2 & L.drug == 1 and years of NY are gen yearNY = year if NY Yes after No in _any_ previous year can be done too. Nick njcoxstata@gmail.com On 14 June 2013 13:03, Ching Wong <ching.y.wong@student.adelaide.edu.au> wrote: > The long dataset is as follows: > > id sex year drug > 1 F 1999 Yes > 1 F 2000 No > 1 F 2001 Yes > 1 F 2002 . > 3 M 1999 No > 3 M 2000 Yes > 3 M 2001 Yes > 3 M 2002 No > 5 F 1999 Yes > 5 F 2000 Yes > 5 F 2001 Yes > 5 F 2002 Yes > 10 M 1999 Yes > 10 M 2000 No > 10 M 2001 Yes > 10 M 2002 No > > Thanks. > > Ching > > On 14 June 2013 21:20, Nick Cox <njcoxstata@gmail.com> wrote: >> Fine. If you tell me what your data are once -reshape-d I will advise. >> >> Nick >> njcoxstata@gmail.com >> >> >> On 14 June 2013 12:45, Ching Wong <ching.y.wong@student.adelaide.edu.au> wrote: >>> Hi Nick, >>> >>> I would like to count "how many times a user said Yes one year and No the next". >>> >>> Thanks. >>> >>> Ching >>> >>> On 14 June 2013 21:11, Nick Cox <njcoxstata@gmail.com> wrote: >>>> I take this to be a new question, but I am unclear what you want. Do you want >>>> >>>> 1. Counting how many times a user said Yes one year and No the next? >>>> >>>> 2. Identifying the first year in which a user said Yes after >>>> previously saying No. >>>> >>>> I fall back on emphasising my previous advice >>>> >>>> Long structure ... is likely to be better for you for most analyses. >>>> >>>> Get these data -reshape-d. You are going to want to do lots of >>>> analyses on different kinds of patterns, and keeping this structure is >>>> really going to strain any user's Stata fluency. >>>> >>>> Nick >>>> njcoxstata@gmail.com >>>> >>>> >>>> On 14 June 2013 12:12, Ching Wong <ching.y.wong@student.adelaide.edu.au> wrote: >>>>> Thanks Nick >>>>> >>>>> Yes, it's all good if I only need to count the first "NO'. >>>>> >>>>> But I would rather to see how to count the first "YES & NO" between >>>>> year of study. >>>>> >>>>> id Drug2009 Drug 2000 >>>>> 1 Yes NO ------->ONE count >>>>> >>>>> Regards, >>>>> >>>>> Ching >>>>> >>>>> On 14 June 2013 20:24, Nick Cox <njcoxstata@gmail.com> wrote: >>>>>> I can't see your value labels from here. But suppose that "No" is a >>>>>> label for value 1. >>>>>> >>>>>> replace year = `j' if Drug`j' == 1 & missing(year) >>>>>> >>>>>> I trust that you will be able to modify that to your situation. >>>>>> >>>>>> >>>>>> Nick >>>>>> njcoxstata@gmail.com >>>>>> >>>>>> >>>>>> On 14 June 2013 11:45, Ching Wong <ching.y.wong@student.adelaide.edu.au> wrote: >>>>>>> Hi Nick, >>>>>>> >>>>>>> So what if -drug*- are numeric variables with value labels, how should >>>>>>> I change my Command? >>>>>>> >>>>>>> >>>>>>> Thanks! >>>>>>> >>>>>>> >>>>>>> Ching >>>>>>> >>>>>>> On 14 June 2013 19:19, Nick Cox <njcoxstata@gmail.com> wrote: >>>>>>>> Code that "doesn't work" but is not shown can not be commented on. >>>>>>>> Long structure (I prefer to avoid the word "format" here) is not >>>>>>>> essential for the problem as I understand it, but it is likely to be >>>>>>>> better for you for most analyses. >>>>>>>> >>>>>>>> The year in which people first said "No" is >>>>>>>> >>>>>>>> gen year = . >>>>>>>> >>>>>>>> qui forval j = 1999/2012 { >>>>>>>> replace year = `j' if Drug`j' == "No" & missing(year) >>>>>>>> } >>>>>>>> >>>>>>>> tab year >>>>>>>> >>>>>>>> So, >>>>>>>> >>>>>>>> 1. Everybody starts out with missing. >>>>>>>> >>>>>>>> 2. If they said "No" in 1999, -year- is changed to 1999 >>>>>>>> >>>>>>>> 3. If they said "No" in 2000, -year- is changed to 2000, but only if >>>>>>>> -year- is missing (so values of 1999 are protected) >>>>>>>> >>>>>>>> and so on. >>>>>>>> >>>>>>>> You didn't explain your datatypes. If -drug*- are numeric variables >>>>>>>> with value labels, the syntax will differ accordingly. >>>>>>>> >>>>>>>> Nick >>>>>>>> njcoxstata@gmail.com >>>>>>>> >>>>>>>> >>>>>>>> On 14 June 2013 10:20, Ching Wong <ching.y.wong@student.adelaide.edu.au> wrote: >>>>>>>> >>>>>>>>> I have the following data set: >>>>>>>>> >>>>>>>>> Id sex drug1999 drug2000 drug2001 drug 2001 >>>>>>>>> >>>>>>>>> 1 F Yes No Yes Unknown >>>>>>>>> >>>>>>>>> 3 M No Yes Yes No >>>>>>>>> >>>>>>>>> 5 F Yes Yes Yes Yes >>>>>>>>> >>>>>>>>> 9 M Unknown Yes No Yes >>>>>>>>> >>>>>>>>> 10 F Yes No Yes No >>>>>>>>> >>>>>>>>> I would like to produce a count of to show the number of people who >>>>>>>>> quit each year, only count the first time they quit and do not care if >>>>>>>>> they change their status to ‘No’ again. >>>>>>>>> >>>>>>>>> What would be the command? I tried to change it to the long formal and >>>>>>>>> use the lag function, but it doesn’t work. >>>>>>>> >>>>>>>> * >>>>>>>> * 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/ >>>>>> >>>>>> * >>>>>> * 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/ >>>> >>>> * >>>> * 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/ >> >> * >> * 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/ * * 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/

**Follow-Ups**:**Re: st: Count the number of changing string values***From:*Sergiy Radyakin <serjradyakin@gmail.com>

**References**:**st: Count the number of changing string values***From:*Ching Wong <ching.y.wong@student.adelaide.edu.au>

**Re: st: Count the number of changing string values***From:*Nick Cox <njcoxstata@gmail.com>

**Re: st: Count the number of changing string values***From:*Ching Wong <ching.y.wong@student.adelaide.edu.au>

**Re: st: Count the number of changing string values***From:*Nick Cox <njcoxstata@gmail.com>

**Re: st: Count the number of changing string values***From:*Ching Wong <ching.y.wong@student.adelaide.edu.au>

**Re: st: Count the number of changing string values***From:*Nick Cox <njcoxstata@gmail.com>

**Re: st: Count the number of changing string values***From:*Ching Wong <ching.y.wong@student.adelaide.edu.au>

**Re: st: Count the number of changing string values***From:*Nick Cox <njcoxstata@gmail.com>

**Re: st: Count the number of changing string values***From:*Ching Wong <ching.y.wong@student.adelaide.edu.au>

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