Nick and Keith,
Thanks a lot for your suggestions.
Deepankar
On Mon, 2006-06-05 at 14:59 +0100, n j cox wrote:
> It is indeed a good idea to tell us the actual problem.
>
> You would be well advised to -reshape- your data from wide
> to long. The other way lies mostly analytic awkwardness and
> programming pain. My guess is that your guess about
> needing nested loops is incorrect.
>
> Assume an identifier -id- as well as the variables
> you report.
>
> keep id dfsize b*
> reshape long b , i(id) j(childno)
>
> Then you get which boy it is by
>
> bysort id (childno) : gen boyno = sum(b == 1)
>
> Then you can relate -boyno- and -childno-.
>
> You may then need to -reshape- back.
>
> Nick
> [email protected]
>
> DEEPANKAR BASU
>
> Thanks for your comments. My actual programming problem is much more
> complicated than just generating p`x'`y' by checking whether `x' == `y'.
> I had given that example as a prototype of the problem I am facing with
> the "if" statement. I could re-phrase my question as: can I do what
> Keith has suggested by using the "if ... else" statement? I give details
> of my actual problem below.
>
> I am working with a (survey-based) dataset which has the following
> variables (related to fertility behaviour) among others:
>
> 1. dfsize: desired family size
> 2. b1: sex of the first child (1=boy, 2=girl, and "missing" if no first
> child in the family)
> 3. b2: sex of second child
> ...
> 11. b9: sex of ninth child
> 12. nboy: number of boys alive in the family
>
> I want to do the following: for each family (observation), I want to see
> whether the k_th boy is the the N_th child, where k goes from 1 to (N-1)
> and N is "dfsize" (the desired family size). If it is the case that the
> k_th boy is the N-th child, then I want to have:
> p`N'`k'=(0.5)^`N';
> Otherwise, I want to have:
> p`N'`k'=0
>
> Note that I will have several nested loops within an outer "if...else"
> statement. The question is: can I do the whole thing differently,
> without using the "if...else" statement?
>
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