Optimizing function speed on 3D array - arrays

Question

I am applying a user-defined function to individual cells of a 3D array. The contents of each cell are one of the following possibilities, all of which are character vectors because of prior formatting:
"N"
"A"
""
"1"
"0"
I want to create a new 3D array of the same dimensions, where cells contain either NA or a numeric vector containing 1 or 0. Thus, I wrote a function named Numericize and used aaply to apply it to the entire array. However, it takes forever to apply it.
Numericize <- function(x){
if(!is.na(x)){
x[x=="N"] <- NA; x
x[x=="A"] <- NA; x
x[x==""] <- NA; x
x <- as.integer(x)
}
return(x)
}
The dimensions original array are 480x866x366. The function takes forever to apply using the following code:
Final.Daily.Array <- aaply(.data = Complete.Daily.Array,
.margins = c(1,2,3),
.fun = Numericize,
.progress = "text")
I am unsure if the speed issue comes from an inefficient Numericize, an inefficient aaply, or something else entirely. I considered trying to set up parallel computing using the plyr package but I wouldn't think that such a simple command would require parallel processing.
On one hand I am concerned that I created a stack overflow for myself (see this for more), but I have applied other functions to similar arrays without problems.
ex.array <- array(dim = c(3,3,3))
ex.array[,,1] <- c("N","A","","1","0","N","A","","1")
ex.array[,,2] <- c("0","N","A","","1","0","N","A","")
ex.array[,,3] <- c("1","0","N","A","","1","0","N","A")
desired.array <- array(dim = c(3,3,3))
desired.array[,,1] <- c(NA,NA,NA,1,0,NA,NA,NA,1)
desired.array[,,2] <- c(0,NA,NA,NA,1,0,NA,NA,NA)
desired.array[,,3] <- c(1,0,NA,NA,NA,1,0,NA,NA)
ex.array
desired.array
Any suggestions?

Answer 1

You can just use a vectorized approach:
ex.array[ex.array %in% c("", "N", "A")] <- NA
storage.mode(ex.array) <- "integer"
You can simply use the second line and it will introduce NAs by coercion.