[R] learning R

Fuchs Ira irafuchs at gmail.com
Wed Feb 25 05:36:17 CET 2009


I was wondering why the following doesn't work:

 > a=c(1,2)
 > names(a)=c("one","two")
 > a
one two
   1   2
 >
 > names(a[2])
[1] "two"
 >
 > names(a[2])="too"
 > names(a)
[1] "one" "two"
 > a
one two
   1   2

I must not be understanding some basic concept here.
Why doesn't the 2nd name change to "too"?

also unrelated:  if I have two vectors and I want to combine them to  
form a matrix ,is cbind (or rbind) the most direct way to do this?

e.g.

x=c(1,2,3)
y=c(3,4,5)
z=rbind(x,y)

alternatively: is there a way to make a matrix with dim=2,3 and then  
to replace the 2nd row with y

something like this (which doesn't work but perhaps there is another  
way to do the equivalent?)

attr(x,"dim")=c(2,3)
x[2,]=y




More information about the R-help mailing list