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From | "Martin Weiss" <martin.weiss1@gmx.de> |
To | <statalist@hsphsun2.harvard.edu> |
Subject | RE: st: RE: reshape command ---listing all the variables changing over time? |
Date | Fri, 14 May 2010 00:09:59 +0200 |
<> Why is it so important to -reshape- to "wide" to -summarize-? It can be done in both data formats. To see the equivalence: *********** webuse reshape1, clear su inc?? reshape long inc ue, i(id) j(year) bys year: su inc *********** HTH Martin -----Original Message----- From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Amanda Fu Sent: Donnerstag, 13. Mai 2010 23:56 To: statalist@hsphsun2.harvard.edu Subject: Re: st: RE: reshape command ---listing all the variables changing over time? Thanks so much, Mr. Weiss! The reason I want to reshape the whole data set wide is that, I got from some coworkers a long-version data set (first stage). I reshape it into wide version to do some basic statistical description, such as the demographic characteristics ( gender, age, race, education description) (second stage). Then, I will reshape the data set back to long version to use the panel data methods such as fixed effect models (third stage). I am required to keep all the variables in the third stage. Maybe I do NOT need to reshape all the demographic variables in the second stage; just include those variables? Thanks a lot! Mandy On Thu, May 13, 2010 at 5:44 PM, Martin Weiss <martin.weiss1@gmx.de> wrote: > > <> > > *********** > ssc d panels > *********** > > may be helpful to check for constant variables within panels. > > > What kind of dataset is it that features 1,500 variables that you want to > -reshape- to wide? I would say that this is not a normal situation when > applying the -reshape- command. You will end up with a dataset with slightly > more than 1,500*(number of distinct values of j) variables. Is that really > intended? Stata is fond of the "long" format for most analyses... > > > HTH > Martin > > > -----Original Message----- > From: owner-statalist@hsphsun2.harvard.edu > [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Amanda Fu > Sent: Donnerstag, 13. Mai 2010 21:57 > To: statalist@hsphsun2.harvard.edu > Subject: st:reshape command ---listing all the variables changing over time? > > Hi all, > > I was wondering if anyone could help me with a problem I met when > using --reshape--command. > > When I tried to reshape a data set from long version to wide version, > I find I need to list all the variables that are not constant in the > --reshape--command. Suppose the data set has 1500 variables changing > over time and 100 constant variables. > ------------------------------------------------------------ > . reshape wide x1-x1500, i(id) j(wave) > ------------------------------------------------------------ > If I miss any of the variables changing over time, the reshape command > will give error message such as "variable XXXX not constant " and will > stop working. But it is so frustrating to separate the constant > variables and not-constant variables and list all of the latter ones > in the reshape command. > > What I used to do is just to drop all the unnecessary variables from > the data set before reshape to reduce the work load here. > > May I know if there is any more efficient way to deal with this problem? > > Thanks for your time! > > Sincerely, > Mandy > * > * 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/ > * * 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/