 thx I was struggling with the DF[,3:4] part of it

On Sun, Apr 25, 2010 at 10:47 AM, John Kane <jrkrideau@yahoo.ca> wrote:

> Here's one way with aggregate()
>
> library(car)  # You probably will need to install it.
>
> aggregate(DF[,3-4], by=list(years), mean,na.rm=TRUE)
>
> recode(x, "c(1,2)='A'; else='B'")
>
> DF$years <- recode(DF$years, "c(5,6,7)= '5-7'")
>
> DF
>
>
> You may also want to have a look at the reshape and plyr packages.
>
> --- On Sun, 4/25/10, steven mosher <moshersteven@gmail.com> wrote:
>
> > From: steven mosher <moshersteven@gmail.com>
> > Subject: [R] Noobie question on aggregate tapply and by
> > To: "r-help" <r-help@r-project.org>
> > Received: Sunday, April 25, 2010, 2:29 AM
> > I have a 43MB dataframe ( 5
> > variables) and I'm trying to summarize subsets
> > of the data.
> > I've RTFM ( not very clear) and looked at a variety of
> > samples but cant seem
> > to figure out
> > how to make these functions work.
> >
> > A sample of what I want to do would be this:
> >
> > ids<-seq(1,50)
> >  years<-c(rep(5,10),rep(6,10),rep(7,10),rep(8,20))
> >
> > data<-c(rep(23.2,7),rep(14.2,17),rep(29.2,6),rep(13.4,10),rep(16.3,5),
> > NA,
> > rep(40,4))
> > data2<-c(rep(22.2,5),rep(13.2,8),NA,
> > rep(29.8,16),rep(12.4,10),rep(16.3,5),
> > rep(38,5))
> >  DF<-data.frame(ids,years,data,data2)
> >
> > That will give you a dataframe that is a good analog of
> > what I have. i
> > would like to calculate means
> > ( with NA removed na.rm) for each level of years.
> >
> >           data  data2
> > 5         xx.
> >    yy.
> > 6         xx
> >    yz
> > 7         ...
> >    ,,,
> > 8         ..
> >   ...
> >
> > And then things like this:
> >
> > 5-7 :   xx     yy
> > 8   :    xy
> >    zz
> >
> >     [[alternative HTML version deleted]]
> >
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> > reproducible code.
> >
>
>
>

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