Re: st: RE: identifying observations where multiple conditions are met

[Sergiy Radyakin <serjradyakin@gmail.com>]

Elizabeth, you actually don't need the "(max)" in your code, since
each variable zero and one is either 1 or missing. It will not have
any other value by construction.

If you insist on using -collapse-, then something like this has the
benefit of not being tied to particular values 0 and 1
--------------------------------------------------
clonevar t1=t
clonevar t2=t
sort id
collapse (min) t1 (max) t2, by(id)
tab id if t1!=t2
--------------------------------------------------
But collapse destroys the dataset.

Sergiy Radyakin

On Wed, Nov 13, 2013 at 3:49 PM, Allred, Elizabeth
<lizard@hsph.harvard.edu> wrote:
> Got ahead of myself!
>
> Collapse (max) not (sum). Sum could give you a number > 1 for both var zero and var one and then the if condition won't be met.
>
> gen zero=1 if type==0
> gen one=1 if type==1
> sort id
> collapse (max) zero one, by(id)
> l id if zero==1 & one==1
>
>
>
> -----Original Message-----
> From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Michael McCulloch
> Sent: Wednesday, November 13, 2013 3:43 PM
> To: statalist@hsphsun2.harvard.edu
> Subject: Re: st: RE: identifying observations where multiple conditions are met
>
> Thanks Elizabeth, yes it's all -id-, where "sometimes type==0, sometimes type==1, that I'm looking for.
>
> The code you suggest makes sense, however at the -collapse- stage, the records disappear -id- in which the "sometimes 0 / sometimes 1" existed prior to -collapse-.
>
>
>
> Best wishes,
> Michael McCulloch
>
> --
> Pine Street Foundation, since 1989
> 124 Pine Street | San Anselmo | California | 94960-2674
> P: (415) 407-1357 | F: (206) 338-2391 | http://www.PineStreetFoundation.org
>
> On Nov 13, 2013, at 12:29 PM, Allred, Elizabeth wrote:
>
>> On further reading, I see... You're trying to find ids with "mixed messages," i.e., sometimes 0 sometimes 1.
>>
>> gen zero=1 if type==0
>> gen one=1 if type==1
>> sort id
>> collapse (sum) zero one, by(id)
>> l id if zero==1 & one==1
>>
>> -----Original Message-----
>> From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Michael McCulloch
>> Sent: Wednesday, November 13, 2013 3:14 PM
>> To: statalist@hsphsun2.harvard.edu
>> Subject: st: identifying observations where multiple conditions are met
>>
>> Hello,
>> I have data of the structure:
>>       id              (range 1 to 300)
>>       type    (for each -id-, should equal only one of two values: 0 or 1).
>>
>> In manual inspection of the data, I see instances exist where, for the same -id-,
>>       some records have type==0, and
>>       other records have type==1.
>>
>> If I enter
>>       . tab id if type==0 & type==1
>> obviously "no observations" is returned.
>>
>> How would I write a command in which I can tabulate all -id- for which some observations exist where type==0, and others where type==1? (At data entry, -type- should have unique for each -id-.)
>>
>>
>> Best wishes,
>> Michael McCulloch
>>
>> --
>> Pine Street Foundation, since 1989
>> 124 Pine Street | San Anselmo | California | 94960-2674
>> P: (415) 407-1357 | F: (206) 338-2391 | http://www.PineStreetFoundation.org
>>
>>
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