R help - Jan 2010 - coerce vector into array - change filling sequence

Dear all,

When I coerce a vector into a multi dimensional array, I would like R to start
filling the array along the last dimension, then the 2nd last etc.
Let's jump straight into an example.

x <- 1 : 24
y <- array(dim=c(2,2,6))

I would like to have:
y[1,1,1] = 1
y[1,1,2] = 2
...
y[1,1,6] = 6
y[1,2,1] = 7
y[1,2,2] = 8
...
y[2,1,1] = 13
...
y[2,2,1] = 19

if I do y<- array(x, dim=c(2,2,6)), i think I will get
y[1,1,1] = 1
y[2,1,1] = 2
(or something not I want) instead.

Of course, I need a fast solution, as I am actually dealing with array of much
larger size.
Any input will be appreciated
Thanks a lot

Hi,

you can permute array dimensions using aperm():

x <- 1 : 24
z <- array(x, dim=c(6,2,2))
y <- aperm(z,perm=c(3,2,1))
y[1,1,]

HTH,
Stephan


Kohleth Chia schrieb:
> Dear all,
> 
> When I coerce a vector into a multi dimensional array, I would like R to
start filling the array along the last dimension, then the 2nd last etc.
> Let's jump straight into an example.
> 
> x <- 1 : 24
> y <- array(dim=c(2,2,6))
> 
> I would like to have:
> y[1,1,1] = 1
> y[1,1,2] = 2
> ...
> y[1,1,6] = 6
> y[1,2,1] = 7
> y[1,2,2] = 8
> ...
> y[2,1,1] = 13
> ...
> y[2,2,1] = 19
> 
> if I do y<- array(x, dim=c(2,2,6)), i think I will get
> y[1,1,1] = 1
> y[2,1,1] = 2
> (or something not I want) instead.
> 
> Of course, I need a fast solution, as I am actually dealing with array of
much larger size.
> Any input will be appreciated
> Thanks a lot
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