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Daniel Nordlund

2009-Aug-24 16:16 UTC

[R] Combining matrices

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

Henrique Dallazuanna

2009-Aug-24 16:36 UTC

head link

[R] Combining matrices

Try this;

do.call(rbind, lapply(split(x, seq(nrow(x))), cbind, y))

On Mon, Aug 24, 2009 at 1:16 PM, Daniel Nordlund
<djnordlund@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
>
> ______________________________________________
> R-help@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-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O

	[[alternative HTML version deleted]]

Marc Schwartz

2009-Aug-24 16:46 UTC

head link

[R] Combining matrices

On Aug 24, 2009, at 11:16 AM, Daniel Nordlund 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


nr.x <- nrow(x)
nr.y <- nrow(y)

 > cbind(x[rep(1:nr.x, each = nr.x), ], y[rep(1:nr.y, nr.y), ])
       [,1] [,2] [,3] [,4] [,5] [,6]
  [1,]    1    1    1    4    4    4
  [2,]    1    1    1    5    5    5
  [3,]    1    1    1    6    6    6
  [4,]    2    2    2    4    4    4
  [5,]    2    2    2    5    5    5
  [6,]    2    2    2    6    6    6
  [7,]    3    3    3    4    4    4
  [8,]    3    3    3    5    5    5
  [9,]    3    3    3    6    6    6



HTH,

Marc Schwartz

Marc Schwartz

2009-Aug-24 16:57 UTC

head link

[R] Combining matrices

On Aug 24, 2009, at 11:46 AM, Marc Schwartz wrote:
>
> On Aug 24, 2009, at 11:16 AM, Daniel Nordlund 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
>
>
>
> nr.x <- nrow(x)
> nr.y <- nrow(y)
>
> > cbind(x[rep(1:nr.x, each = nr.x), ], y[rep(1:nr.y, nr.y), ])
>      [,1] [,2] [,3] [,4] [,5] [,6]
> [1,]    1    1    1    4    4    4
> [2,]    1    1    1    5    5    5
> [3,]    1    1    1    6    6    6
> [4,]    2    2    2    4    4    4
> [5,]    2    2    2    5    5    5
> [6,]    2    2    2    6    6    6
> [7,]    3    3    3    4    4    4
> [8,]    3    3    3    5    5    5
> [9,]    3    3    3    6    6    6


Actually, correction...that will work in this case, but in the general  
case, I believe that it needs to be:

x <- matrix(rep(c(1,2,3),3),3)
y <- matrix(rep(c(4,5,6,7),3),4)

 > x
      [,1] [,2] [,3]
[1,]    1    1    1
[2,]    2    2    2
[3,]    3    3    3

 > y
      [,1] [,2] [,3]
[1,]    4    4    4
[2,]    5    5    5
[3,]    6    6    6
[4,]    7    7    7


nr.x <- nrow(x)
nr.y <- nrow(y)


 > cbind(x[rep(1:nr.x, each = nr.y), ], y[rep(1:nr.y, nr.x), ])
       [,1] [,2] [,3] [,4] [,5] [,6]
  [1,]    1    1    1    4    4    4
  [2,]    1    1    1    5    5    5
  [3,]    1    1    1    6    6    6
  [4,]    1    1    1    7    7    7
  [5,]    2    2    2    4    4    4
  [6,]    2    2    2    5    5    5
  [7,]    2    2    2    6    6    6
  [8,]    2    2    2    7    7    7
  [9,]    3    3    3    4    4    4
[10,]    3    3    3    5    5    5
[11,]    3    3    3    6    6    6
[12,]    3    3    3    7    7    7


We need to replicate each row by the number of rows in the other matrix.

HTH,

Marc

Daniel Nordlund

2009-Aug-24 17:08 UTC

head link

[R] Combining matrices

> -----Original Message-----
> From: Marc Schwartz [mailto:marc_schwartz at me.com] 
> Sent: Monday, August 24, 2009 9:57 AM
> To: Daniel Nordlund
> Cc: r help
> Subject: Re: [R] Combining matrices
> 
> 
> On Aug 24, 2009, at 11:46 AM, Marc Schwartz wrote:
> 
> >
> > On Aug 24, 2009, at 11:16 AM, Daniel Nordlund 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
> >
> >
> >
> > nr.x <- nrow(x)
> > nr.y <- nrow(y)
> >
> > > cbind(x[rep(1:nr.x, each = nr.x), ], y[rep(1:nr.y, nr.y), ])
> >      [,1] [,2] [,3] [,4] [,5] [,6]
> > [1,]    1    1    1    4    4    4
> > [2,]    1    1    1    5    5    5
> > [3,]    1    1    1    6    6    6
> > [4,]    2    2    2    4    4    4
> > [5,]    2    2    2    5    5    5
> > [6,]    2    2    2    6    6    6
> > [7,]    3    3    3    4    4    4
> > [8,]    3    3    3    5    5    5
> > [9,]    3    3    3    6    6    6
> 
> 
> 
> Actually, correction...that will work in this case, but in 
> the general  
> case, I believe that it needs to be:
> 
> x <- matrix(rep(c(1,2,3),3),3)
> y <- matrix(rep(c(4,5,6,7),3),4)
> 
>  > x
>       [,1] [,2] [,3]
> [1,]    1    1    1
> [2,]    2    2    2
> [3,]    3    3    3
> 
>  > y
>       [,1] [,2] [,3]
> [1,]    4    4    4
> [2,]    5    5    5
> [3,]    6    6    6
> [4,]    7    7    7
> 
> 
> nr.x <- nrow(x)
> nr.y <- nrow(y)
> 
> 
>  > cbind(x[rep(1:nr.x, each = nr.y), ], y[rep(1:nr.y, nr.x), ])
>        [,1] [,2] [,3] [,4] [,5] [,6]
>   [1,]    1    1    1    4    4    4
>   [2,]    1    1    1    5    5    5
>   [3,]    1    1    1    6    6    6
>   [4,]    1    1    1    7    7    7
>   [5,]    2    2    2    4    4    4
>   [6,]    2    2    2    5    5    5
>   [7,]    2    2    2    6    6    6
>   [8,]    2    2    2    7    7    7
>   [9,]    3    3    3    4    4    4
> [10,]    3    3    3    5    5    5
> [11,]    3    3    3    6    6    6
> [12,]    3    3    3    7    7    7
> 
> 
> We need to replicate each row by the number of rows in the 
> other matrix.
> 
> HTH,
> 
> Marc
> 
Thanks to all who responded (including those off-list).  I now have options
to apply to solving my programming task.  

Thanks,

Dan

Gabor Grothendieck

2009-Aug-24 17:10 UTC

head link

[R] Combining matrices

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
>
> ______________________________________________
> 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.
>

Gabor Grothendieck

2009-Aug-25 06:06 UTC

head link

[R] Combining matrices

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
>>
>> ______________________________________________
>> 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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