retain array class when operation results in 2-dimensional matrix - arrays

Question

I have an array that can have one or more pages or sheets (my names for the third dimension). I am attempting to perform operations on the array. When there is only one sheet or page the result of the operation is a matrix. I would like the result to be an array. Is there a way to retain the class array even when the result of the operation has only 1 sheet or page?
Here is an example. I would like my.var.2 and my.var.3 to be arrays. The variable my.pages is set to 1 here, which seems to be causing the problem. However, my.pages can be >1. If my.pages <- 2 then my.var.2 and my.var.3 are arrays.
set.seed(1234)
my.rows <- 10
my.columns <- 4
my.pages <- 1
my.var.1 <- array( rnorm((my.rows*my.columns*my.pages), 10, 2),
c(my.rows,my.columns,my.pages))
my.var.1
my.var.2 <- 2 * my.var.1[,-my.columns,]
my.var.3 <- 10 * my.var.1[,-1,]
class(my.var.2)
class(my.var.3)
my.var.2 <- as.array(my.var.2)
my.var.3 <- as.array(my.var.3)
class(my.var.2)
class(my.var.3)
my.var.2 <- as.array( 2 * my.var.1[,-my.columns,])
my.var.3 <- as.array(10 * my.var.1[,-1,] )
class(my.var.2)
class(my.var.3)
The switch to matrix causes problems when I try to use my.var.1 and my.var.2 in nested for-loops.
The following if statement seems to solve the problem, but also seems a little clunky. Is there a more elegant solution?
if(my.pages == 1) {my.var.2 <- array(my.var.2, c(my.rows,(my.columns-1),my.pages))}

Answer 1

From help([):
Usage:
x[i, j, ... , drop = TRUE]
...
drop: For matrices and arrays. If 'TRUE' the result is coerced to
the lowest possible dimension (see the examples). This only
works for extracting elements, not for the replacement. See
'drop' for further details.
Your code, revisited:
set.seed(1234)
my.rows <- 10
my.columns <- 4
my.pages <- 1
my.var.1 <- array( rnorm((my.rows*my.columns*my.pages), 10, 2),
c(my.rows,my.columns,my.pages))
my.var.2 <- 2 * my.var.1[,-my.columns,,drop=FALSE]
my.var.3 <- 10 * my.var.1[,-1,,drop=FALSE]
class(my.var.2)
## [1] "array"
class(my.var.3)
## [1] "array"