Re: st: creating expanded records with indicator variables, where different ID's reside in the same rows

[Jeph Herrin <junk@spandrel.net>]

How about create two files and merge

  preserve
  keep if !mi(A)
  ren A ID
  gen byte A=1
  sort ID
  save theAs
  restore
  keep if !mi(B)
  ren B ID
  gen byte B=1
  sort ID
  merge 1:1 ID using theAs
  replace A=0 if mi(A)
  replace B=0 if mi(B)

?

hth,
Jeph



Michael McCulloch wrote:
> Hello,
> I have a data structure that has been gathered as follows, where each 
> cell contains the subject ID if A is true, and similarly for B. 
> Therefore, for subject 5, I have A=yes and B=yes, whereas for subjects 6 
> and 11, only B=yes.
>
> A    B
> 5    5
> 6    11
>
> I'd like to transform the data structure such that each row would have 
> ID, and indicator variables for A and B.
> id    A    B
> 5    1    1
> 6    0    1
> 11    0    1
>
> I've tried an approach like this, where I create indicator variables but 
> A and B, but am not sure how to "expand" from  the data structure where 
> different ID's reside in the same rows.
>     . gen id1=a
>     . gen id2=b
>     . gen aa=1 if a!=.
>     . gen bb=1 if b!=.
>
> It also looks like -reshape- is not suitable because different ID's 
> reside in the same rows.
> Any advice would be appreciated.
>
>
>
> Michael McCulloch
> Pine Street Foundation
> 124 Pine Street
> San Anselmo, CA 94960-2674
> tel:    415-407-1357
> fax:     206-338-2391
> mm@pinestreetfoundation.org
>
>
>
>
>
>
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