# st: RE: RE: RE: Resdesigning dyadic data formats

 From "Neumayer,E" To Subject st: RE: RE: RE: Resdesigning dyadic data formats Date Wed, 21 Apr 2004 14:23:34 +0100

```Nick, great! Now, one more complication. Your advice works if there are dyads in just one year. But assume now that there is also a year variable. OK, with "fillin c1 c2 year" I get the dataset in a nice rectangular shape. What adjustment do I need to make for the other four lines:

gen max = max(c1,c2)
gen min = min(c1,c2)
bysort max min (x) : assert _N == 2
by max min: replace x = x[1] if missing(x)

Thanks, Eric

-----Original Message-----
From: Nick Cox [mailto:n.j.cox@durham.ac.uk]
Sent: 21 April 2004 11:49
To: statalist@hsphsun2.harvard.edu
Subject: st: RE: RE: Resdesigning dyadic data formats

(not tested; shorter solutions may exist)

gen max = max(c1,c2)
gen min = min(c1,c2)
bysort max min (x) : assert _N == 2
by max min: replace x = x[1] if missing(x)

For example:
2-1 and 1-2 both have maximum 2 and minimum 1.

We sort so that ties on -min- and -max- are together, and check that
they do indeed occur in pairs.

Within each pair, we sort on -x-, so that missings
go to the end. Then we copy downwards within each pair.

Nick
n.j.cox@durham.ac.uk

Neumayer,E
>
> thanks. I can see how this creates a nice rectangular
> dataset. However, how could I get Stata to take the values of
> the x-variables over? At the moment, the "1-2" pair, for
> example, has 567 as value for the x-variable, but after
> fillin, the "2-1" pair, which now exists, is empty for the
> x-variable, but I'd like to have it as 567 as well. Any help
> greatly appreciated again.
>
> Best, Eric
>
> ------------------------------
>
> Date: Tue, 20 Apr 2004 14:18:13 +0100
> From: "Nick Cox" <n.j.cox@durham.ac.uk>
> Subject: st: RE: Resdesigning dyadic data formats
>
> fillin c1 c2
> replace x = . if _fillin
> drop _fillin
>
> Nick
> n.j.cox@durham.ac.uk
>
> Neumayer,E
>
> > I have a "dyadic" dataset that looks like this (which is the
> > traditional way of setting up such data):
> >
> > c1	c2	x
> > 1	2	567
> > 1	3	345
> > 1	4	7
> > 1	5	348
> > 2	3	47
> > 2	4	3
> > 2	5	48
> > 3	4	23424
> > 3	5	347
> > 4	5	234
> >
> > The "c1" and "c2" are identifiers for the two dyads. I would
> > like to re-design the data to have it in the following format:
> >
> > c1	c2	x
> > 1	1
> > 1	2	567
> > 1	3	345
> > 1	4	7
> > 1	5	348
> > 2	1	567
> > 2	2
> > 2	3	47
> > 2	4	3
> > 2	5	48
> > 3	1	345
> > 3	2	47
> > 3	3
> > 3	4	23424
> > 3	5	347
> > 4	1	7
> > 4	2	3
> > 4	3	23424
> > 4	4
> > 4	5	234
> > 5	1	348
> > 5	2	48
> > 5	3	347
> > 5	4	234
> > 5	5
> >
> > Note that now the identical pairs (1-1, 2-2, 3-3, 4-4, 5-5)
> > have missing x-values, of course, and that all x-values exist
> > twice now (e.g., once for 1-5, and once for 5-1). I know, one
> > could do this redesigning by hand, but given that my actual
> > dataset is far bigger, I am looking for a way to let Stata do
> > the work for me. Any ideas?

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