Create Matrix of 2 Dim from two vectors

Hi,

First, create a MATRIX of the correct size:
xy <- matrix(nrow=3, ncol=3)

Then, in your for loop, you need to index each cell correctly, like this:
xy[i,j]

Finally, if you want to assign "1,4" to each cell, you need to paste 
x[i] and y[j] together, like this:
xy[i,j]<-paste(x[i],y[j], sep=",")

With the brackets if you want:
xy[i,j]<-paste("(", x[i], ",", y[j], ")", sep="")

Or easier like this:
xy <- matrix(rep(x,3),nrow=3, ncol=3)
apply(xy, 1, FUN=paste, y, sep=",")

HTH,
Ivan

Le 11/8/2010 11:15, abotaha a ?crit :

Hello,

I have two data.

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

How do i create matrix of 3 by 3 from this two, such that

  (1,4)  (1,5)  (1,6)
  (2,4)  (2,5)  (2,6)
  (3,4)  (3,5)  (3,6)

I tried some thing like this:

xy<- as.data.frame(c(0,0,0), dim=c(3,3))
for(i in 1:3)
for(j in 1:3)
xy[i][j]<-c(x[i],y[j])

but i got errors..!!!!
any help would appreciate

Ivan CALANDRA
PhD Student
University of Hamburg
Biozentrum Grindel und Zoologisches Museum
Abt. S?ugetiere
Martin-Luther-King-Platz 3
D-20146 Hamburg, GERMANY
+49(0)40 42838 6231
ivan.calandra at uni-hamburg.de

**********
http://www.for771.uni-bonn.de
http://webapp5.rrz.uni-hamburg.de/mammals/eng/mitarbeiter.php