Coerces spray objects to arrays. Includes off-by-one functionality via
option offbyone.
# S3 method for spray
as.array(x, offbyone=FALSE, compact=FALSE, ...)
# S3 method for spray
dim(x)spray object
Boolean with default FALSE meaning to interpret
the index entries as positions in their dimension, and TRUE
meaning to add one to index values so that zero entries appear in
the first place
Boolean with default FALSE meaning to translate
the spray as is, and TRUE meaning to add constants to each
column of the index matrix so that the resulting array is as small
as possible
Further arguments, currently ignored
Returns an array of dimension dim(S). The “meat” of the
function is
out <- array(0, dS)
out[ind] <- value(S)
Argument offbyone defaults to FALSE; but if it is set to
TRUE, it effectively adds one from the index matrix, so a zero
entry in the index matrix means the first position in that dimension.
After the subtraction, if performed, the function will not operate if any index is less than 1.
# NOT RUN {
M <- matrix(sample(0:4,28,replace=TRUE),ncol=4)
S <- spray(M,sample(7),addrepeats=TRUE)
A <- as.array(S,offbyone=TRUE)
S <- spray(matrix(sample(1:4,28,replace=TRUE),ncol=4),sample(7))
A <- as.array(S) # S has no zero indices
stopifnot(all(S[index(S),drop=TRUE] == A[index(S)]))
# }