OK. Suppose you -sort- a numeric variable:
sort myvar
Then, if at least one value of -myvar-
is missing, it follows that the last value
will be missing, as any missing values have been -sort-ed to
that end. So that you could do this
sort myvar
if missing(myvar[_N]) drop myvar
to get rid of a variable with any missing values.
Also, if a numeric variable were all missing,
then
sort myvar
if missing(myvar[1]) & missing(myvar[_N]) drop myvar
would drop such a variable.
On the whole, however,
if <condition> <command>
doesn't much feature in decisions on whole
variables.
-dropmiss- itself just uses -count- for this problem and does
nothing to the -sort- order, even internally.
Nick
[email protected]
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]]On Behalf Of Alejandro
> Delafuente
> Sent: 19 June 2005 16:38
> To: [email protected]
> Subject: RE: st: RE: Using results from correlation matrices
> to pinpoint
> variables
>
>
> okey, in that case the solution was: using the command
> dropmiss with the
> option any, so that all variables with missings would be
> dropped out. As for
> the if distinction between qualifier and command, that was
> already clear to
> me, or at least that is what I thought.
> Alex
> In message
> <031173627889364697C50B3B266CBB8A101BC6@GEOGMAIL.geog.ad.dur.ac.uk>
> [email protected] writes:
> > A thread is best closed by saying what the
> > solution was, not that you found a solution....
> >
> > Nick
> > [email protected]
> >
> > Alejandro Delafuente
> >
> > > many thanks Nick. I sorted out the problem.
> > >
> > > In message
> > >
> <031173627889364697C50B3B266CBB8A101BAF@GEOGMAIL.geog.ad.dur.ac.uk>
> > > [email protected] writes:
> > > > My guess is that what you are getting what you
> > > > ask for, but that it is not what you want.
> > > >
> > > > The difference between
> > > >
> > > > if <condition> <command>
> > > >
> > > > and
> > > >
> > > > <command> if <condition>
> > > >
> > > > is profound. For one documentation, see
> > > > http://www.stata.com/support/faqs/lang/ifqualifier.html
> > > >
> > > > I am not clear what you want precisely. If you
> > > > want to drop a variable if and only if all observations
> > > > are missing, then
> > > >
> > > > . search dropmiss
> > > >
> > > > for a convenience command.
> > > >
> > > > Nick
> > > > [email protected]
> > > >
> > > > Alejandro Delafuente
> > > > >
> > > > > Dear Nick, thanks for your advice. With some little
> > > > > adjustments it worked out!
> > > > > Also, taking advantage of your generosity let me ask you a
> > > > > quick question: am
> > > > > trying to drop some monthly variables in a time sequence
> > > > > (from january 1961 to
> > > > > dec 2001) with missings in them. My code looks as follows:
> > > > > foreach var of varlist jan* feb* ... dec* {
> > > > > if `var' ==. {
> > > > > drop `var'
> > > > > }
> > > > > }
> > > > > But for some reason it is not working. Can you tell why?
> > > > > As always, many thanks.
> >
> > *
> > * For searches and help try:
> > * http://www.stata.com/support/faqs/res/findit.html
> > * http://www.stata.com/support/statalist/faq
> > * http://www.ats.ucla.edu/stat/stata/
> >
>
> --
> Alejandro de la Fuente
> QEH/Department of International Development
> Oxford University
> *
> * For searches and help try:
> * http://www.stata.com/support/faqs/res/findit.html
> * http://www.stata.com/support/statalist/faq
> * http://www.ats.ucla.edu/stat/stata/
>
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
