Thank you all for replying.
The codes I am using to create the duration variable are:
tsset hhid period ;
spell brand ;
bysort _spell: gen duration = _N ;
drop _* ;
It works perfect.
Albert
On 4/6/06, Nick Cox <[email protected]> wrote:
> The problem identified by Scott is that
> Brand is a string variable, at least
> as created by him when setting up the
> example.
>
> This would be another way
>
> tsset hhid Period
> tsspell, fcond(Switch == 1 | L.Period == .)
> bysort hhid _spell : gen duration = _N
>
> L.Period == . catches the first observation
> in each panel.
>
> tsspell, fcond(Switch == 1 | _n == 1)
>
> would also work, but this hinges on knowing
> how -tsspell- does the job.
>
> Nick
> [email protected]
>
> Scott Merryman
>
> > A slight modification is necessary:
> >
> > tsset hhid per
> > encode b, gen(b2)
> > tsspell b2
> > bysort hhid _spell: replace _seq = _seq[_N]
> > rename _seq duration
> > drop _* b2
> >
> >
> > -tsspell- creates _spell by:
> > = by hhid: gen long _spell = sum((brand != L.brand) | (_n ==
> > 1) & __000001)
> >
> > while -spell- uses explicit subscripting.
>
>
> *
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>
*
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