[R] Paste every two columns together

[Dennis Murphy]

Hi:

Don't know about performance, but this is fairly simple for operating
on atomic vectors:

x <- c("A", "A", "G", "T", "C", "G")
apply(embed(x, 2), 1, paste0, collapse = "")
[1] "AA" "GA" "TG" "CT" "GC"

Check the help page of embed() for details.

Dennis

On Wed, Jan 28, 2015 at 3:55 PM, Kate Ignatius <kate.ignatius at gmail.com> wrote:
> I have genetic data as follows (simple example, actual data is much larger):
>
> comb =
>
> ID1 A A T G C T G C G T C G T A
>
> ID2 G C T G C C T G C T G T T T
>
> And I wish to get an output like this:
>
> ID1 AA TG CT GC GT CG TA
>
> ID2 GC TG CC TG CT GT TT
>
> That is, paste every two columns together.
>
> I have this code, but I get the error:
>
> Error in seq.default(2, nchar(x), 2) : 'to' must be of length 1
>
> conc <- function(x) {
>   s <- seq(2, nchar(x), 2)
>   paste0(x[s], x[s+1])
> }
>
> combn <- as.data.frame(lapply(comb, conc), stringsAsFactors=FALSE)
>
> Thanks in advance!
>
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