Re: st: Is there a command for picking off the lowest values of an Identified group?

[Ian Breunig <ianbreunig@gmail.com>]

Thanks a lot Neil!  You saved me some time this morning.

Ian

On Thu, Jul 29, 2010 at 9:49 AM, Neil Shephard <nshephard@gmail.com> wrote:
> On Thu, Jul 29, 2010 at 3:43 PM, Ian Breunig <ianbreunig@gmail.com> wrote:
>> I want to find the age of the mother's youngest child.
>>
>> If, for example, I have data as follows:
>>
>> Mother ID:        Child ID:     Child Age:
>>
>> 1                         a                  1
>> 1                         b                  2
>> 1                         c                  3
>> 1                         d                  4
>> 2                         e                  10
>> 2                         f                   10
>> 2                         g                  12
>> 3                         h                  5
>> 3                         i                   7
>>
>> Is there a simple command to tell me the youngest age for every Mother
>> ID or  do I have to use a do loop and if statement to do this?  If so
>> can anyone help me out with the most efficient way to code the do
>> loop.
>
> No loop required, the following should do what you are after (note
> I've assumed variable names, as the above are illegal in Stata as
> spaces in variable names are not permitted)
>
> bysort mother_id (child_age) : gen youngest_child = child_age[1]
>
> The variable youngest_child will be constant within each grouping of
> mother_id and will contain the age of the youngest child (by virtue of
> having sorted the data on that variable).
>
> Neil
>
> --
> "... no scientific worker has a fixed level of significance at which
> from year to year, and in all circumstances, he rejects hypotheses; he
> rather gives his mind to each particular case in the light of his
> evidence and his ideas." - Sir Ronald A. Fisher (1956)
>
> Email - nshephard@gmail.com
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