[R] Calculating mean together with split

[David Barron]

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
>
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>


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