Hi
r-help-boun...@r-project.org napsal dne 28.01.2010 17:40:01:
> Thank you, Dennis and Petr.
>
> One more question: when aggregating to one es per id, how would I go
about
> keeping the other variables in the data.frame (e.g., keeping the value
for
> the first row of the other variables, such as mod2) e.g.:
>
> # Dennis provided this example (notice how mod2 is removed from the
output):
>
> > with(x, aggregate(list(es = es), by = list(id = id, mod1 = mod1),
mean))
> id mod1 es
> 1 3 1 0.20
> 2 1 2 0.30
> 3 2 4 0.15
>
> # How can I get this output (taking the first row of the other variable
in
> the data.frame):
If I remember it correctly in my suggestion I used something like
aggregate(x[,-columns.mod1 and mod2], by = x[, columns.mod1 and mod2,
mean)
Which shall use mod2 as aggregating variable.
Does it result in output you wanted?
Regards
Petr
>
> id es mod1 mod2
>
> 1 .30 2 wai
> 2 .15 4 other
> 3 .20 1 itas
>
>
> Thank you,
>
> AC
>
>
> On Thu, Jan 28, 2010 at 1:29 AM, Petr PIKAL <petr.pi...@precheza.cz>
wrote:
>
> > HI
> >
> > r-help-boun...@r-project.org napsal dne 28.01.2010 04:35:29:
> >
> > > > Hi All,
> > > >
> > > > I'm conducting a meta-analysis and have taken a data.frame with
> > multiple
> > > > rows per
> > > > study (for each effect size) and performed a weighted average of
> > effect
> > > > size for
> > > > each study. This results in a reduced # of rows. I am particularly
> > > > interested in
> > > > simply reducing the additional variables in the data.frame to the
> > first row
> > > > of the
> > > > corresponding id variable. For example:
> > > >
> > > > id<-c(1,2,2,3,3,3)
> > > > es<-c(.3,.1,.3,.1,.2,.3)
> > > > mod1<-c(2,4,4,1,1,1)
> > > > mod2<-c("wai","other","calpas","wai","itas","other")
> > > > data<-as.data.frame(cbind(id,es,mod1,mod2))
> >
> > Do not use cbind. Its output is a matrix and in this case character
> > matrix. Resulting data frame will consist from factors as you can
check by
> >
> >
> > str(data)
> >
> > data<-data.frame(id=id,es=es,mod1=mod1,mod2=mod2)
> >
> >
> > > >
> > > > data
> > > >
> > > > id es mod1 mod2
> > > > 1 1 0.3 2 wai
> > > > 2 2 0.1 4 other
> > > > 3 2 0.2 4 calpas
> > > > 4 3 0.1 1 itas
> > > > 5 3 0.2 1 wai
> > > > 6 3 0.3 1 wai
> > > >
> > > > # I would like to reduce the entire data.frame like this:
> >
> > E.g. aggregate
> >
> > aggregate(data[, -(3:4)], data[,3:4], mean)
> > mod1 mod2 id es
> > 1 4 calpas 2 0.3
> > 2 1 itas 3 0.2
> > 3 1 other 3 0.3
> > 4 4 other 2 0.1
> > 5 1 wai 3 0.1
> > 6 2 wai 1 0.3
> >
> > doBy or tapply or ddply from plyr library or ....
> >
> > Regards
> > Petr
> >
> > > >
> > > > id es mod1 mod2
> > > >
> > > > 1 .30 2 wai
> > > > 2 .15 4 other
> > > > 3 .20 1 itas
> > > >
> > > > # If possible, I would also like the option of this (collapsing on
id
> > and
> > > > mod2):
> > > >
> > > > id es mod1 mod2
> > > > 1 .30 2 wai
> > > > 2 0.1 4 other
> > > > 2 0.2 4 calpas
> > > > 3 0.1 1 itas
> > > > 3 0.25 1 wai
> > > >
> > > > Any help is much appreciated!
> > > >
> > > > AC Del Re
> > > >
> > >
> > > [[alternative HTML version deleted]]
> > >
> > > ______________________________________________
> > > R-help@r-project.org mailing list
> > > https://stat.ethz.ch/mailman/listinfo/r-help
> > > PLEASE do read the posting guide
> > http://www.R-project.org/posting-guide.html
> > > and provide commented, minimal, self-contained, reproducible code.
> >
> >
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@r-project.org mailing list
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> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
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