Re: st: Question about fillin

[Austin Nichols <austinnichols@gmail.com>]

André Gyllenram <a_gyllenram@hotmail.com> :
This might do what you want.

clear
input indiv str1 s period
       1      C        1
       1      E        1
       1      A        2
       1      F        2
       2      G        1
       2      H        1
       2      G        2
       2      K        2
end
encode s, g(stock)
g t=period
egen maxperiods=max(t), by(indiv)
egen nperiods=count(t), by(indiv stock)
g x=maxperiods-nperiods+1
bys indiv stock (t): replace x=1 if _n<_N
expand x
bys indiv stock (t): replace period=_n
list, sepby(indiv) noo


On Thu, Feb 14, 2013 at 9:16 AM, André Gyllenram
<a_gyllenram@hotmail.com> wrote:
> Hello,
>
> I have a question about the command fillin.
>
> It is not possible to combine this with by. But can you do in some other way?
>
> I would like to write like this:
>
> by individual: fillin individual stock period.
>
>
> My data looks like this;
>
> INDIVIDUAL    STOCK   PERIOD
> 1             C        1
> 1             E        1
> 1             A        2
> 1             F        2
>
> 2             G        1
> 2             H        1
> 2             I        2
> 2             K        2
>
> And I would like to add observations with missing data so that in every time period there is a row for all stocks that the individual owns in any period. Individual 1 owns
> stock C, E, A and F in period 1 or 2. This means that i want a row for these stocks in every time period for individual 1.
>
> Individual 2 owns stock G, H, I an K in period 1 or 2. So for every time period I want a row for these stocks for individual 2. In this example I want to add observations so the data looks like this:
>
>
> INDIVIDUAL   STOCK   PERIOD
> 1            A       1
> 1            C       1
> 1            E       1
> 1            F       1
> 1            A       2
> 1            C       2
> 1            E       2
> 1            F       2
>
> 2            G       1
> 2            H       1
> 2            I       1
> 2            K       1
> 2            G       2
> 2            H       2
> 2            I       2
> 2            K       2
>
> So in this example I want to add 8 rows. If I write fillin individual period I would add much more rows than i want to since the individuals together own stocks A, C, E, F, G, H, I
> and K.
>

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