This is easier done long.
save safecopy
gen long id = _n
reshape long PID, i(id)
bysort id (PID) : gen same = PID == PID[_n-1]
bysort id (same) : replace same = same[_N]
reshape wide
Nick
[email protected]
Seb Buechte
> you could take a "brute force" approach by comparing each var with all
> the other vars using two loops:
>
> gen interlock=0
> foreach var1 of varlist PID1 PID2 .... {
> foreach var2 of varlist PID2 PID3.... {
> if "`var1'"!="`var2'" { // making sure you do not compare the
> var with itself
> replace interlock=1 if `var1' == `var2'
> }
> }
> }
>
> I am not too sure how long it will take to run through these loops.
Derek Darves
> > I have a group of variables:
> >
> > PID1 - PID15
> >
> > PID* takes on values from 1 to 8000, and many are missing.
> >
> > Basically, I would like to make a new variable, called interlock,
> > that is equal to 1 if any of the variables in the list are equal to
> > any other variable in the list (not including itself, of course).
> > For example, if PID5==705 and PID14==705 I would like like
> interlock==1
> >
> > Likewise, if none of the the variables in PID* take on the value of
> > any of the other variables in PID*, I would like interlock==0
> >
> > I tried this:
> > egen interlock = group(pid1_a pid1_b pid2_a pid2_b pid3_a
> > pid3_b pid4_a pid4_b pid5_a pid5_b pid6_a pid6_b pid7_a
> > pid7_b pid8_a pid8_b pid9_a pid9_b pid10_a pid10_b pid11_a
> > pid11_b pid12_a pid12_b pid13_a pid13_b pid14_a
> pid14_b pid15_a)
> >
> > , but it returned all missing values when I know that some share a
> > common value in two of the PID* fields.
> >
> > Lastly, not that it should matter, but the above is a simplifying
> > example. In my actual dataset I have about 130 PID*
> variables. I just
> > mention this in case I am hitting some kind of memory limitation (I
> > am not receiving any errors when I run the command, though, it just
> > doesn't work).
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