Re: st: using loops in collapse command

[Nick Cox <njcoxstata@gmail.com>]

See also the thread started just one week ago by

http://www.stata.com/statalist/archive/2012-03/msg01141.html

On Mon, Apr 2, 2012 at 3:35 PM, Jocelyn Michael
<michaeljocelyn31@gmail.com> wrote:
> I am a new stata user and have been trying to write a loop to accomplish a task.
>
> My data looks like this:
>
>
> id                 Year               Value 1
> A               Jan1991             0.92
> A               Feb1991             0.93
> A               Mar1991             0.24
> A               APr1991             0.83
> ..
> ..
> B               Jan1991             0.67
> B               Feb1991             0.45
> ..
>
> What I am trying to achieve is to write a loop that multiplies value1
> for each id and returns one number for each year - sort of like a
> collapse command but instead of the sum, I want the product. That is
> for A for 1991, (0.92*0.93*0.24*0.83).

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