[R] populating an array
Tony Plate
tplate at acm.org
Fri Oct 16 17:39:37 CEST 2009
R doesn't access arrays like C, use [i,j] to access a 2-d array, e.g.:
> my_array <- array(0,dim=c(2,2))
> for(i in seq(1,2,by=1)){
+ for(j in seq(1,2,by=1)){
+ my_array[i,j] = i+j
+ }
+ }
>
> my_array
[,1] [,2]
[1,] 2 3
[2,] 3 4
>
tdm wrote:
> Hi,
>
> Can someone please give me a pointer as to how I can set values of an array?
>
> Why does the code below not work?
>
> my_array <- array(dim=c(2,2))
> my_array[][] = 0
> my_array
> [,1] [,2]
> [1,] 0 0
> [2,] 0 0
>
> for(i in seq(1,2,by=1)){
> for(j in seq(1,2,by=1)){
> my_array[i][j] = 5
> }
> }
>
> Warning messages:
> 1: In my_array[i][j] = 5 :
> number of items to replace is not a multiple of replacement length
> 2: In my_array[i][j] = 5 :
> number of items to replace is not a multiple of replacement length
>
> my_array
> [,1] [,2]
> [1,] 5 0
> [2,] 5 0
>
>
>
More information about the R-help
mailing list