[R] how do I get means by factor?

[BXC (Bendix Carstensen)]

tapply( x, f, mean )

maybe with

tapply( x, f, mean, na.rm=T )

----------------------
Bendix Carstensen
Senior Statistician
Steno Diabetes Center
Niels Steensens Vej 2
DK-2820 Gentofte
Denmark
tel: +45 44 43 87 38
mob: +45 30 75 87 38
fax: +45 44 43 07 06
bxc at steno.dk
www.biostat.ku.dk/~bxc
----------------------



> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch 
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Chris
> Sent: Wednesday, February 23, 2005 10:38 PM
> To: r-help at stat.math.ethz.ch
> Subject: [R] how do I get means by factor?
> 
> 
> I want the mean of a response variable for each level of a 
> factor in a data.frame.  How is this done?
> 
> 	[[alternative HTML version deleted]]
> 
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