Best way to turn a list into a data.frame - R-help

Mon, Apr 6, 2009 6:49 AM #

Hello,

What is the best way to turn a list into a data.frame?

I have a list with something like:
$`3845`
 [1] "04010" "04012" "04360"

$`1029`
[1] "04110" "04115"

And I would like to get a data frame like the following:

3845 "04010"
3845 "04012"
3845 "04360"
1029 "04110"
1029 "04115"

Any ideas?

Dan

**************************************************************
Daniel Brewer, Ph.D.

Institute of Cancer Research
Molecular Carcinogenesis
Email: daniel.brewer at icr.ac.uk
**************************************************************

The Institute of Cancer Research: Royal Cancer Hospital, a charitable Company Limited by Guarantee, Registered in England under Company No. 534147 with its Registered Office at 123 Old Brompton Road, London SW7 3RP.

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Hadley Wickham

Mon, Apr 6, 2009 7:11 AM #

On Mon, Apr 6, 2009 at 8:49 AM, Daniel Brewer <daniel.brewer at icr.ac.uk> wrote:

l <- list("3845" = c("a", "b", "c"), "1029" = c("d", "e","f"))

libary(reshape)
melt(l)

Hadley

http://had.co.nz/

Luc Villandre

Mon, Apr 6, 2009 7:25 AM #

Hi Daniel,

In your case, I guess you could use:

col1 = rep(attributes(my.list)$names,lapply(my.list,length)) ;
col2 = unlist(my.list,use.names=FALSE) ;
my.data.frame = as.data.frame(cbind(col1,col2)) ;

This should work well.

Cheers,

Luc

Daniel Brewer wrote:

Daniel Brewer

Mon, Apr 6, 2009 7:31 AM #

Thanks thats marvellous.  Does the trick beautifully.

Dan

hadley wickham wrote:

**************************************************************
Daniel Brewer, Ph.D.

Institute of Cancer Research
Molecular Carcinogenesis
Email: daniel.brewer at icr.ac.uk
**************************************************************

The Institute of Cancer Research: Royal Cancer Hospital, a charitable Company Limited by Guarantee, Registered in England under Company No. 534147 with its Registered Office at 123 Old Brompton Road, London SW7 3RP.

This e-mail message is confidential and for use by the a...{{dropped:2}}