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# Re: st: Identify reciprocated ties in directed network with -netsis-

 From Nick Cox To "statalist@hsphsun2.harvard.edu" Subject Re: st: Identify reciprocated ties in directed network with -netsis- Date Sat, 15 Jun 2013 11:16:26 +0100

```I have not used -netsis- (from SJ 12-1; please explain _where_
user-written programs you refer to come from) but this appears to
yield easily to a simple trick.

gen first = cond(source < target, source, target)
gen second = cond(source < target, target, source)
bysort month first second : gen recip = mod(_N, 2)  == 0

Inequalities apply to strings as well as numbers, e.g.

. di  ("James" < "Keira")
1

so sorting reduces pairs to comparable form ("James" "Keira"   and
"Keira" "James" both are sorted to "James" "Keira"   and 7  42 and 42
7 are both sorted to 7 42).

See

SJ-8-4  dm0043  . Tip 71: The problem of split identity, or how to group dyads
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N. J. Cox
Q4/08   SJ 8(4):588--591                                 (no commands)
tip on how to handle dyadic identifiers

http://www.stata-journal.com/sjpdf.html?articlenum=dm0043

for more.

Nick
njcoxstata@gmail.com

On 15 June 2013 10:15, Claudio Tagliapietra
<claudio.tagliapietra@unibo.it> wrote:
> I am using -netsis- in Stata 12.1 SE in Windows 7, to analyze a directed network. The data is stored as an arc list, as follows
>
> Example 1. Input.
>
> month   source   target
> ------------------------------
> 1           Andrew  Peter
> 1           Peter     Andrew
> 1           James   Peter
> 2           Peter     James
> 2           Andrew  Peter
> 2           James    Peter
>
> "source" and "target" are stored as integer ids.
>
> I want to create a dummy "recipr" that indicates which ties (arcs) are reciprocated in each month. The output should be:
>
> Example 2. Output.
>
> month   source   target    recipr
> -----------------------------------------
> 1           Andrew  Peter      1
> 1           Peter     Andrew   1
> 1           James   Peter       0
> 2           Peter     James     1
> 2           Andrew  Peter       0
> 2           James    Peter      1
>
> Is this currently possible with -netsis-?
> Alternatives?
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```