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

[Bert Gunter]

Sorry, I failed to cc the list.

-- Bert





---------- Forwarded message ----------
From: Bert Gunter <bgunter at gene.com>
Date: Mon, Mar 30, 2015 at 8:36 AM
Subject: Re: [R] changing column labels for data frames inside a list
To: Vikram Chhatre <crypticlineage at gmail.com>


You really really need to spend (more?) time with a good R tutorial
before posting further. Your questions are entirely due to your
ignorance of standard language syntax that you should learn if you
intend to use R. Of course, feel free to ask for help if there are
places in the tutorials where, after an honest effort, you remain
flummoxed.

Cheers,
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 8:19 AM, Vikram Chhatre
<crypticlineage at gmail.com> wrote:
> First of all, thank you for all the quick replies.  Here is a solution that
> worked for me.
>
> mylist2 <- lapply(mylist, function(e){colnames(e) <- paste0('pop',1:12);
> return(e)})
>
>> head(mylist2[[1]])
>         pop1  pop2  pop3  pop4  pop5  pop6  pop7  pop8  pop9 pop10 pop11
> pop12
> 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
>
> While we are at this, I wanted to create a 13th column in each data frame
> for average of each row.
>
> # Calculate average
> myavg <- lapply(mylist2, function(e) rowSums(mylist2)/12)
>
> # Attach to the main data frame
> mylist3 <- cbind(mylist2, myavg)
>
> This does not work the way I imagined it would.  The myavg vector is
> attached directly to mylist2, not to individual dataframes within.
>
> p.s. Is it a standard convention to always copy the reply to the last
> person who responded?
>
> On Mon, Mar 30, 2015 at 10:56 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.
>> >
>>
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>>
>> ______________________________________________
>> 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.