[R] changing column labels for data frames inside a list

[Sven E. Templer]

On 30 March 2015 at 17:31, Bert Gunter <gunter.berton at gene.com> wrote:

> Sarah's statement is correct.
>
> So is yours. They are not contradictory, and I believe Sarah's point
> was that the OP needed to learn the appropriate syntax.
>
>
That's why I pointed to ?return.
Sarah's statement was not so clear (and might have been misleading) for me
regarding the R expertise of the OP.


> -- Bert
>
> Bert Gunter
> Genentech Nonclinical Biostatistics
> (650) 467-7374
>
> "Data is not information. Information is not knowledge. And knowledge
> is certainly not wisdom."
> Clifford Stoll
>
>
>
>
> On Mon, Mar 30, 2015 at 7:56 AM, Sven E. Templer <sven.templer at gmail.com>
> wrote:
> > On 30 March 2015 at 16:47, Sarah Goslee <sarah.goslee at gmail.com> wrote:
> >
> >> colnames(e) <- paste0('pop',1:12)
> >>
> >> isn't a function and doesn't return anything.
> >>
> >
> > But
> > function(e){colnames(e) <- paste0('pop', 1:2)}
> > is a function and it returns something (the last evaluated expression! -
> > here the paste0 return):
> >
> >> mylist2 <- lapply(mylist, function(e){colnames(e) <- paste0('pop',
> 1:2)})
> >> mylist2
> > [[1]]
> > [1] "pop1" "pop2"
> >
> > [[2]]
> > [1] "pop1" "pop2"
> >
> > [[3]]
> > [1] "pop1" "pop2"
> >
> >  from ?return:
> >
> > If the end of a function is reached without calling return, the value of
> > the last evaluated expression is returned.
> >
> >>
> >> > mylist <- list(
> >> + data.frame(a = runif(10), b = runif(10)),
> >> + data.frame(c = runif(10), d = runif(10)),
> >> + data.frame(e = runif(10), f = runif(10)))
> >> > mylist2 <- lapply(mylist, function(e){colnames(e) <- paste0('pop',
> 1:2);
> >> e})
> >> > colnames(mylist2[[1]])
> >> [1] "pop1" "pop2"
> >>
> >> Sarah
> >>
> >> On Mon, Mar 30, 2015 at 9:54 AM, Vikram Chhatre
> >> <crypticlineage at gmail.com> wrote:
> >> >> summary(mygenfreqt)
> >> >                   Length Class  Mode
> >> > dat1.str 59220  -none- numeric
> >> > dat2.str 59220  -none- numeric
> >> > dat3.str 59220  -none- numeric
> >> >
> >> >> head(mylist[[1]])
> >> >            1     2     3     4     5     6     7     8     9    10
> 11
> >> >  12
> >> > L0001.1 0.60 0.500 0.325 0.675 0.600 0.500 0.500 0.375 0.550 0.475
> 0.350
> >> > 0.275
> >> > L0001.2 0.40 0.500 0.675 0.325 0.400 0.500 0.500 0.625 0.450 0.525
> 0.650
> >> > 0.725
> >> >
> >> > I want to change 1:12 to pop1:pop12
> >> >
> >> > mylist<- lapply(mylist, function(e) colnames(e) <- paste0('pop',1:12))
> >> >
> >> > What this is doing is replacing the data frames with just names
> >> > pop1:pop12.  I just want to replace the column labels.
> >> >
> >> > Thanks for any suggestions.
> >> >
> >>
> >> --
> >> Sarah Goslee
> >> http://www.functionaldiversity.org
> >>
> >> ______________________________________________
> >> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> >> 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 at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > 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.
>

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