[R] function by

Thu Sep 30 18:21:23 CEST 2004

?by
FUN: a function to be applied to data frame subsets of 'data'.

...: further arguments to 'FUN'.

by (SS, year, sum)

/E

Emilie Berthiaume wrote:

>Hi,
>
>I'm just getting started with R and I'm having problems with some simple
>operations: I want to get the the sum of the column "SStot" for each year using
>the function by.  The data set is named "SS".  I've tried this:
>
>by (SS, year, sum(SStot))
>
>and it's not working.  Is it because there's a different number of rows for each
>year?  How else can I do this?
>
>--
>Emilie Berthiaume
>Graduate student
>Biology Departement
>UniversitÃ© de Sherbrooke
>2500 boul. de l'UniversitÃ©
>Sherbrooke, QuÃ©bec
>J1K 2R1 CANADA
>
>TÃ©l: 1-819-821-8000 poste 2059
>Fax: 1-819-821-8049
>Emilie.Berthiaume at USherbrooke.ca
>
>______________________________________________
>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
>
>  
>

-- 
Dipl. bio-chem. Witold Eryk Wolski         
MPI-Moleculare Genetic
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tel: 0049-30-83875219                   'v'
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      wolski at molgen.mpg.de