[R] Combining matrices

Gabor Grothendieck
Tue, 25 Aug 2009 06:06:44 -0000

My prior solution was not correct.

If the idea is to combine each row of x with each row
of y then convert the matrices to data frames and
perform and outer join with SQL like this:

library(sqldf)

X <- as.data.frame(x)
Y <- as.data.frame(y)

as.matrix(sqldf("select * from X, Y", method = "raw"))

See http://sqdfl.googlecode.com

On Mon, Aug 24, 2009 at 1:10 PM, Gabor
Grothendieck<ggrothendieck at gmail.com> wrote:
> Try this:
>
> kronecker(cbind(x, y), rep(1, 3))
>
>
> On Mon, Aug 24, 2009 at 12:16 PM, Daniel Nordlund<djnordlund at
verizon.net> wrote:
>> If I have two matrices like
>>
>> x <- matrix(rep(c(1,2,3),3),3)
>> y <- matrix(rep(c(4,5,6),3),3)
>>
>> How can I combine ?them to get ?
>>
>> 1 1 1 4 4 4
>> 1 1 1 5 5 5
>> 1 1 1 6 6 6
>> 2 2 2 4 4 4
>> 2 2 2 5 5 5
>> 2 2 2 6 6 6
>> 3 3 3 4 4 4
>> 3 3 3 5 5 5
>> 3 3 3 6 6 6
>>
>> The number of rows and the actual numbers above are unimportant, they
are given so as to illustrate how I want to combine the matrices. ?I.e., I am
looking for a general way to combine the first row of x with each row of y, then
the second row of x with y, ....
>>
>> Thanks,
>>
>> Dan
>>
>> Daniel Nordlund
>> Bothell, WA USA
>>
>> Thanks for
>>
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>