Puzzled at generating combinations

3 messages · Ajay Shah, Henrique Dallazuanna, John Kane

Original

1

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Ajay Shah

Tue, Mar 18, 2008 8:05 AM #

I have two data frames. Suppose the first has rows

r1
r2
r3

and the second has rows

R1
R2
R3

I'd like to generate the data frame:

    r1   R1
    r1   R2
    r1   R3
    r2   R1
    r2   R2
    r2   R3
    r3   R1
    r3   R2
    r3   R3

How would I go about doing this? I'm sure there's a clean way to do it
but I find myself thinking in loops.

Ajay Shah                                      http://www.mayin.org/ajayshah  
ajayshah at mayin.org                             http://ajayshahblog.blogspot.com
<*(:-? - wizard who doesn't know the answer.

Henrique Dallazuanna

Tue, Mar 18, 2008 9:40 AM #

Try:

expand.grid(col2, col1)

On 18/03/2008, Ajay Shah <ajayshah at mayin.org> wrote:

______________________________________________
R-help at r-project.org mailing list
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.

Henrique Dallazuanna
Curitiba-Paran?-Brasil
25? 25' 40" S 49? 16' 22" O

John Kane

Tue, Mar 18, 2008 9:50 AM #

Will something like this work?
x <- data.frame(xx=c("r1", "r2", "r3"), yy=c(1,2,3))
y <- data.frame(aa=c("R1", "R2", "R3"), bb=c(10,12,
14))

merge(x,y)

--- Ajay Shah <ajayshah at mayin.org> wrote:

______________________________________________
R-help at r-project.org mailing list
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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