R help - Mar 2006 - merge two vectors of the same length into one?

Dear all,

       I have a question about merge two character vectors of the same
length into one.

For example:

      X= c('A', 'B', 'C', 'A', 'D',  
.......)      # 26 possible
alphabet values with length 1000
      Y=c('B', 'A', 'C', 'A', 'C',  
........)      # 26 possible
aphabet values with length  1000

     after using table ( X,Y ), I will get a matrix of 26*26.  But I
want to sort these values from large to small, that is to say, I want
to get an output like this;

      AB   75
      AC   60
      CC   58
      ....

How can I get this kind of output?

Thank you very much!


--
Zhiqiang Ye

What about this:
> X <- c("A", "B", "C", "A",
"D", "A")
> Y <- c("B", "A", "C", "A",
"C", "B")
> XY <- paste(X, Y, sep="")
> sort(table(XY), decreasing=TRUE)
XY
AB AA BA CC DC
 2  1  1  1  1



On 3/26/06, Zhiqiang Ye <yezhiqiang@gmail.com>
wrote:
>
> Dear all,
>
>        I have a question about merge two character vectors of the same
> length into one.
>
>
--
Sarah Goslee
http://www.stringpage.com

	[[alternative HTML version deleted]]

On 3/26/2006 11:26 AM, Zhiqiang Ye wrote:
> Dear all,
> 
>        I have a question about merge two character vectors of the same
> length into one.
> 
> For example:
> 
>       X= c('A', 'B', 'C', 'A', 'D',
.......)      # 26 possible
> alphabet values with length 1000
>       Y=c('B', 'A', 'C', 'A', 'C', 
........)      # 26 possible
> aphabet values with length  1000
> 
>      after using table ( X,Y ), I will get a matrix of 26*26.  But I
> want to sort these values from large to small, that is to say, I want
> to get an output like this;
> 
>       AB   75
>       AC   60
>       CC   58
>       ....
> 
> How can I get this kind of output?
I am not sure I understand what you want (e.g. I would have expected to 
see BA in your list).

But you can get the table of pairs via

table(paste(X, Y, sep=""))

and you can sort it if you want, e.g.

 > X= c('A', 'B', 'C', 'A', 'D',
'A')
 > Y= c('B', 'A', 'C', 'A', 'C',
'B')
 > table(paste(X,Y,sep=""))

AA AB BA CC DC
  1  2  1  1  1
 > sort(table(paste(X,Y,sep="")), dec=TRUE)

AB AA BA CC DC
  2  1  1  1  1

> AB AA BA CC DC
>   2  1  1  1  1
>
Yeah, thank you two for your help.  BTW, can I change the output like this way:

AB  2
AA  1
BA  1
CC  1
DC  1

Thanks a lot!

--
Zhiqiang Ye