[R] Aggregating data

[Gabor Grothendieck]

I meant: calculates the means of variables 4 and 5 based on the levels of
variable 1.  Is that what you want?

On 11/29/06, Gabor Grothendieck <ggrothendieck at gmail.com> wrote:
> Using the builtin data set CO2:
>
>   aggregate(CO2[4:5], CO2[1], mean)
>
> calculates the means of variables 4 and 5 based combinations of the
> levels of variable 1.  Is that what you want?
>
>
>
> On 11/29/06, David Kaplan <dkaplan at education.wisc.edu> wrote:
> > Chuck and others.  Here is the problem I need help on.  Thanks.
> >
> > --------------------
> >
> > I want to follow-up on a question I had a week or so ago.  I want to
> > aggregate a very large data set.  Generally in a program such as SPSS,
> > one chooses a so-called "break variable" that is the variable, and then
> > the remaining variables are aggregated by that variable with some
> > summary statistic calculated - such as the mean.
> >
> > I played with "aggregate" in R and found that it requires a "by"
> > statement listing the variables.  But I don't see how I can aggregate on
> > one variable and create the summary statistics on the remaining
> > variables.  I hope that was clear.  Thanks for an advice in advance.
> >
> > David
> > ===========================================================================
> > David Kaplan, Ph.D.
> > Professor
> > Department of Educational Psychology
> > University of Wisconsin - Madison
> > Educational Sciences, Room, 1061
> > 1025 W. Johnson Street
> > Madison, WI 53706
> >
> > email: dkaplan at education.wisc.edu
> > homepage: http://www.education.wisc.edu/edpsych/facstaff/kaplan/kaplan.htm
> > Phone: 608-262-0836
> > ===========================================================================
> >
> > Chuck Cleland wrote:
> > > David Kaplan wrote:
> > >> The problem is that this doesn't seem to give what I want.  I did look
> > >> at this.  Perhaps doBy will work - haven't tried it yet.  But, any other
> > >> suggestions are much appreciated.
> > >
> > > David:
> > >   Your posts on aggregating came to the list without any text in the
> > > body of the message (I believe Petr sent a response based only on the
> > > subject).  You might get more specific and helpful suggestions if you
> > > send a small example of what you are trying to do and why aggregate()
> > > does not work for you.  Also, be sure to send messages in plain text
> > > rather than HTML.
> > >
> > > hope this helps,
> > >
> > > Chuck Cleland
> > >
> > >> ===========================================================================
> > >> David Kaplan, Ph.D.
> > >> Professor
> > >> Department of Educational Psychology
> > >> University of Wisconsin - Madison
> > >> Educational Sciences, Room, 1061
> > >> 1025 W. Johnson Street
> > >> Madison, WI 53706
> > >>
> > >> email: dkaplan at education.wisc.edu
> > >> homepage: http://www.education.wisc.edu/edpsych/facstaff/kaplan/kaplan.htm
> > >> Phone: 608-262-0836
> > >> ===========================================================================
> > >>
> > >> Petr Pikal wrote:
> > >>> Similar answer as last time
> > >>>
> > >>> aggregate, tapply, by or ppackage doBy
> > >>>
> > >>> HTH
> > >>>
> > >>> PS. If you want to add some other text then subject in your post do
> > >>> not use HTML posting as recommended in posting guide.
> > >>>
> > >>> Petr
> > >>>
> > >>>
> > >>> On 28 Nov 2006 at 22:04, David Kaplan wrote:
> > >>>
> > >>> Date sent:          Tue, 28 Nov 2006 22:04:09 -0600
> > >>> From:               David Kaplan <dkaplan at education.wisc.edu>
> > >>> To:                 r-help at stat.math.ethz.ch
> > >>> Subject:            [R] Aggregating data
> > >>>
> > >>>> ______________________________________________
> > >>>> R-help at stat.math.ethz.ch mailing list
> > >>>> https://stat.ethz.ch/mailman/listinfo/r-help
> > >>>> PLEASE do read the posting guide
> > >>>> http://www.R-project.org/posting-guide.html and provide commented,
> > >>>> minimal, self-contained, reproducible code.
> > >>> Petr Pikal
> > >>> petr.pikal at precheza.cz
> > >>>
> > >> ______________________________________________
> > >> R-help at stat.math.ethz.ch mailing list
> > >> https://stat.ethz.ch/mailman/listinfo/r-help
> > >> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> > >> and provide commented, minimal, self-contained, reproducible code.
> > >>
> > >
> >
> > ______________________________________________
> > R-help at stat.math.ethz.ch mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> >
>