[R] List to data frame

[Joshua Wiley]

Hi,

Here is another option if you already have a list you want to convert.
 This will handle different elements of the list being different
lengths.

#Using your example data
mydata <- list(c(1,2,3),c(4,5,6))

data.frame(
 OriginalListIndex = rep(x = seq_along(mydata),
   times = unlist(lapply(mydata, length))),
 Item = unlist(mydata)
)

#Just to demonstrate that this method works generally
mydata <- list(c(1,2,3), c(7,6), c(3,4,5,6,7,8,9))

data.frame(
 OriginalListIndex = rep(x = seq_along(mydata),
   times = unlist(lapply(mydata, length))),
 Item = unlist(mydata)
)


HTH,

Josh

On Mon, Jul 26, 2010 at 7:46 AM, Johannes Graumann
<johannes_graumann at web.de> wrote:
> Hi,
>
> Any ideas on how to efficiently convert
>
>> list(c(1,2,3),c(4,5,6))
>
> to
>
>> data.frame(OriginalListIndex=c(1,1,1,2,2,2),Item=c(1,2,3,4,5,6))
>
> Thanks for any hints,
>
> Joh
>
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-- 
Joshua Wiley
Ph.D. Student, Health Psychology
University of California, Los Angeles
http://www.joshuawiley.com/