[R] How Can I Concatenate Every Row in a Data Frame with Every Other Row?

[jim holtman]

Try this:

> x <- data.frame(a=1:100, b=100:1, c=sample(100))
> # assume even number of rows: bind the even/odd together
> even <- seq(nrow(x)) %% 2
> new.x <- cbind(x[even==1,], x[even==0,])
>
>
> head(new.x)
    a   b  c a.1 b.1 c.1
1   1 100 69   2  99  60
3   3  98 24   4  97  26
5   5  96 71   6  95  43
7   7  94 17   8  93  70
9   9  92 10  10  91  79
11 11  90 56  12  89  50
>


On Sat, Mar 21, 2009 at 12:01 PM, Donald Macnaughton <donmac at matstat.com> wrote:
> I have a data frame with roughly 500 rows and 120 variables.  I would like
> to generate a new data frame that will include one row for each PAIR of
> rows in the original data frame and will include all 120 + 120 = 240
> variables from the two rows.  I need only one row for each pair, not two
> rows.  Thus the new data frame will contain 500 x 499 / 2 = 124,750 rows.
>
> Is there an easy way to do this with R?
>
> Thanks in advance,
>
> Don Macnaughton
>
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>



-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?