[R] why these expressions cann't be nested?

[Peter Dalgaard]

ronggui <ronggui.huang at gmail.com> writes:

> > x<-matrix(1:10,5)
> > x=t(x)
> > colnames(x) <- letters[1:5]
> > x
>      a b c d  e
> [1,] 1 2 3 4  5
> [2,] 6 7 8 9 10
> 
> If I try to nest the above expressions,II get the error. I know there
> is something wrong with it(and I won't write command like that
> now),but I don't why.So anyone can explain it for me? Thank you!
> 
> > x<-matrix(1:10,5)
> > colnames(t(x)) <- letters[1:5]
> Error: couldn't find function "t<-"

You're trying to modify x by modifying t(x), and there is no method to
do so. You can write one if you want:

> "t<-" <- function(x,value)"<-"(x,t(value))
> x<-matrix(1:10,5)
>  colnames(t(x)) <- letters[1:5]
> x
  [,1] [,2]
a    1    6
b    2    7
c    3    8
d    4    9
e    5   10

Of course, setting rownames(x) would be easier....

-- 
   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
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