[R] Calculating mean together with split

[David Barron]

Of course, aggregate will work too, depends on how you want the output
to be formatted.  You could also look at summarize in the Hmisc
package.

On 20/09/06, David Barron <mothsailor at googlemail.com> wrote:
> Sorry, that should have been package gdata, not gtools...they're both
> in the same bundle, though.
>
> On 20/09/06, Rainer M Krug <rkrug at sun.ac.za> wrote:
> > Hi
> >
> > I have a table called npl containing results of simulations.
> >
> > It contains about 19000 entries and the structure looks like this:
> >
> >   NoPlants                  sim run year DensPlants
> > 1        6 lng_cs99_renosterbos   1    4    0.00192
> > .
> > .
> > .
> >
> >
> > it has 43 different entries for sim and year goes from 1 to 100, and run
> > from 1 to 5.
> >
> > I would like to calculate the mean of DensPlants for each simulation and
> > each year seperately, i.e. calculating the mean for all combinations of
> > sim and year over run.
> >
> > I can use
> >
> > split(npl, npl$sim)
> >
> > to split npl into different groups each containing the entries for one
> > parameterset - but where to go from there?
> >
> > Rainer
> >
> > --
> > Rainer M. Krug, Dipl. Phys. (Germany), MSc Conservation
> > Biology (UCT)
> >
> > Department of Conservation Ecology and Entomology
> > University of Stellenbosch
> > Matieland 7602
> > South Africa
> >
> > Tel:            +27 - (0)72 808 2975 (w)
> > Fax:            +27 - (0)21 808 3304
> > Cell:           +27 - (0)83 9479 042
> >
> > email:  RKrug at sun.ac.za
> >         Rainer at krugs.de
> >
> > ______________________________________________
> > 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.
> >
>
>
> --
> =================================
> David Barron
> Said Business School
> University of Oxford
> Park End Street
> Oxford OX1 1HP
>


-- 
=================================
David Barron
Said Business School
University of Oxford
Park End Street
Oxford OX1 1HP