[R] RV: By sentence

[Petr Klasterecky]

Well, you want a mean of length BY sex, so look at by()...
See ?by
by(your.data.frame,sex,mean)

Petr

Jorge Cornejo Donoso napsal(a):
> 
> Hi dear listers
> 
> 	Do you know how to made a mean by one or more categorical variables?
> 	I can do that quite easy on SAS by in R I just can't do it E.g.
> 	Some fishes
> 	Sex 	Lenght
> 	male	15
> 	fema	20
> 	fema	17
> 	fema	19
> 	male  18
> 
> 	So the idea is mean(Lenght) by sex, in order to have sex: Male
> mean=XX Sex: Fema mean=YY
> 	In this case is quite easy to do it by a loop, but I have a huge DB
> so is not an option. Any suggestion?
> 
> 	Thanks in advance!
> 
> --
> 
> Jorge Cornejo Donoso
> 
> Universidad Austral de Chile
> 
> Portales 73, Coyhaique,CP 5950000, Region de Aisén, Chile Tel +56 67 244520
> Fax +56 67 239377
> 
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> 
> 

-- 
Petr Klasterecky
Dept. of Probability and Statistics
Charles University in Prague
Czech Republic