[R] grouping

[Petr Savicky]

On Tue, Apr 03, 2012 at 02:21:36PM -0400, Val wrote:
> Hi All,
> 
> On the same data  points
> x=c(46, 125 , 36 ,193, 209, 78, 66, 242 , 297,45 )
> 
> I want to have have the following output  as data frame
> 
> x       group   group mean
> 46       1        42.3
> 125     2        89.6
> 36       1        42.3
> 193     3        235.25
> 209     3        235.25
> 78       2        89.6
> 66       2        89.6
> 242     3        235.25
> 297     3        235.25
> 45       1        42.3
> 
> I tried the following code
> 
> 
> dat <- data.frame(xc=split(x, cut(x, quantile(x, prob=c(0, .333, .66 ,1))))
> gxc <- with(dat, tapply(xc, group, mean))
> dat$gxc <- gxce[as.character(dat$group)]
> txc=dat$gxc
> 
> it did not work for me.

David Winsemius suggested to use ave(), when you asked this
question for the first time. Can you have look at it?

Petr Savicky.