Another approach, as your needs are very specific (take every other item in the
second column and the unique values of columns 1) would be to index, use unique
and put it together with data.frame (or cbind).
data.frame(family = unique(x[, 1]), kid1 = x[c(T, F), 2], kid2 = x[c(F, T), 2])
Cheers,Tyler
> From: jorgeivanve...@gmail.com
> Date: Tue, 20 Mar 2012 00:29:08 -0400
> To: alyaba...@gmail.com
> CC: r-help@r-project.org
> Subject: Re: [R] Reshape from long to wide
>
> Hi aly,
>
> Try
>
> # your data
> x <- structure(list(family = c(14L, 14L, 15L, 15L, 17L, 17L, 18L,
> 18L, 20L, 20L, 24L, 24L, 25L, 25L, 27L, 27L, 28L, 28L, 29L, 29L
> ), length = c(18L, 7L, 7L, 21L, 50L, 21L, 36L, 21L, 36L, 42L,
> 56L, 42L, 43L, 56L, 15L, 42L, 7L, 42L, 56L, 49L)), .Names = c("family",
> "length"), class = "data.frame", row.names = c(NA, -20L))
>
> # processing
> require(plyr)
> ddply(x, .(family), function(df) c(kid1 = df$length[1], kid2 =
> df$length[2]))
> family kid1 kid2
> 1 14 18 7
> 2 15 7 21
> 3 17 50 21
> 4 18 36 21
> 5 20 36 42
> 6 24 56 42
> 7 25 43 56
> 8 27 15 42
> 9 28 7 42
> 10 29 56 49
>
> HTH,
> Jorge.-
>
>
> On Mon, Mar 19, 2012 at 7:01 PM, aly <> wrote:
>
> > Hi,
> >
> > I'm a total beginner in R and this question is probably very simple but
> > I've
> > spent hours reading about it and can't find the answer. I'm trying to
> > reshape a data table from long to wide format. I've tried reshape() and
> > cast() but I get error messages every time and I can't figure why. In my
> > data, I have the length of two fish from each family. My data table (called
> > fish) looks like this:
> >
> > family length
> > 14 18
> > 14 7
> > 15 7
> > 15 21
> > 17 50
> > 17 21
> > 18 36
> > 18 21
> > 20 36
> > 20 42
> > 24 56
> > 24 42
> > 25 43
> > 25 56
> > 27 15
> > 27 42
> > 28 7
> > 28 42
> > 29 56
> > 29 49
> >
> > I want it to look like this:
> >
> > family kid1 kid2
> > 14 18 7
> > 15 7 21
> > 17 50 21
> > 18 36 21
> > 28 36 42
> > 24 56 42
> > 25 43 56
> > 27 15 42
> > 28 7 42
> > 29 56 49
> >
> > I've tried:
> >
> > >cast( fish, fam~length)
> >
> > and got the error message:
> >
> > Using length as value column. Use the value argument to cast to override
> > this choice
> > Error in `[.data.frame`(data, , variables, drop = FALSE) :
> > undefined columns selected
> >
> > Then I rename the columns:
> >
> > >myvars<-c("fam","length")
> > >fish<-fish[myvars]
> >
> > and try the cast() again with no luck (same error)
> >
> > By using reshape() I don't get the results I want:
> >
> > >reshape(rdm1, timevar="fam", idvar=c("length"), direction="wide")
> > > head(first)
> > length
> > 14.20 14
> > 14.19 7
> > 15.25 21
> > 17.30 50
> > 18.32 36
> > 20.36 42
> >
> > Can someone help with this? Thanks a lot!
> >
> >
> >
> >
> > --
> > View this message in context:
> > http://r.789695.n4.nabble.com/Reshape-from-long-to-wide-tp4486875p4486875.html
> > Sent from the R help mailing list archive at Nabble.com.
> >
> > ______________________________________________
> > 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
> 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
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.
