Typo time: if todrop == _n
Nick
[email protected]
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]]On Behalf Of Michael
> Blasnik
> Sent: 07 December 2006 18:26
> To: [email protected]
> Subject: st: Re: Repeating values
>
>
> ...
> I think this will do what you want (assuming that you also
> have a variable
> named company in your dataset):
>
> gsort company -year
> by company: gen todrop=sum(Var1==Var1[1] & Var1==Var1[_n+1])
> by company: replace Var1=. if todrop=_n
> drop todrop
>
> The data are sorted in reverse time (as Nick mentioned) and
> then todrop is
> created as a counter for the cumulative number of
> observations equal to the
> first (final timewise) observation and also equal to the next
> observation
> (prior timewise). Then, if the observation number equals
> todrop, it should
> be changed to missing.
>
> Michael Blasnik
>
> ----- Original Message -----
> From: "Thomas Erdmann" <[email protected]>
> To: <[email protected]>
> Sent: Thursday, December 07, 2006 11:56 AM
> Subject: st: Repeating values
>
>
> > Hi,
> >
> > I am working with some variables that or "wrong" in the
> sense that if one
> > share was taken off the market (i.e. the company was
> dissolved), the last
> > value of the variable is repeated instead of containing
> missing values.
> >
> > e.g.
> >
> > Status Year Var1
> > Listed 1991 0.9
> > Listed 1992 0.95
> > Listed 1993 0.93
> > Delisted 1994 0.93
> > Delisted 1995 0.93
> > ..
> > Delisted 2006 0.93 (value is always repeated up to
> present time)
> >
> > Whereas years 1994-2006 should contain missing values. I
> came up with this
> > cleaning process:
> >
> > foreach X of varlist var1 var2 var3 {
> > generate `X'new=`X'
> > replace `X'new=. if `X'==L.`X'
> > replace `X'=`X'new
> > drop `X'new
> > }
> >
> > Which is okay, but also sets the value to missing if one
> observation for a
> > listed company repeats, so it also deletes observations
> that would be
> > fine.
> >
> > Any suggestions on how I can only replace the "wrong" values?
>
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