Re: st: RE: cleaning data efficiently

[Maria Ana Vitorino <vitorino@wharton.upenn.edu>]

Thanks for the quick response.
This is very helpful.
Ana


On Oct 28, 2011, at 11:24 AM, Nick Cox wrote:

> 1. -egen- has a -mode()- function.
>
> egen mode = mode(regionname), by(regioncode)
>
> 2.
>
> For that you need something like
>
> egen tag = tag(mode regioncode)
> egen ndistinctvalues = total(tag), by(mode)
>
> See also for a review
>
> SJ-8-4  dm0042  . . . . . . . . . . . .  Speaking Stata: Distinct  
> observations
>        (help distinct if installed)  . . . . . .  N. J. Cox and G.  
> M. Longton
>        Q4/08   SJ 8(4):557--568
>        shows how to answer questions about distinct observations
>        from first principles; provides a convenience command
>
> 3.
>
> ssc inst groups
> help groups
> groups regionname regioncode
>
> (there are other ways, but I like this one)
>
> Nick
> n.j.cox@durham.ac.uk
>
> Vitorino, Maria Ana
>
> Suppose I have the following data:
>
> regioncode  regionname
> X  AAA
> Y BBB
> Z CCC
> X   .
> X AAA
> Y BBB
> Z   .
> Z AAA
> Z CCC
> Z CCC
>
> Assume also that the regioncode variable is correct but there are  
> some errors and missing values in the regionname variable.
> 1) Is there an efficient way to fix the entries in the regionname  
> variable? (For this we need to assume that the correspondence  
> between regioncode and regioname that occurs more frequently is the  
> correct one.)
>
> I usually deal with this type of issues using several lines of code  
> so I'm wondering if there is a more efficient way making use of some  
> stata commands that I'm not familiar with.
>
> Also, if, after correcting the mistakes, I want to
> 2)check if the correspondence between the two variables is unique
> 3) create a table with regionname regioncode and frequency of  
> observations (but not a two-way table)
> What is the most efficient way?
>
> *
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