as.array
Coerce spray objects to arrays
Coerces spray objects to arrays. Includes off-by-one functionality via
option offbyone.
- Keywords
- symbolmath
Usage
# S3 method for spray
as.array(x, offbyone=FALSE, compact=FALSE, ...)
# S3 method for spray
dim(x)Arguments
- x
spray object
- offbyone
Boolean with default
FALSEmeaning to interpret the index entries as positions in their dimension, andTRUEmeaning to add one to index values so that zero entries appear in the first place- compact
Boolean with default
FALSEmeaning to translate the spray as is, andTRUEmeaning to add constants to each column of the index matrix so that the resulting array is as small as possible- ...
Further arguments, currently ignored
Details
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.
Value
Returns an array of dimension dim(S). The “meat” of the
function is
out <- array(0, dS)
out[ind] <- value(S)
Examples
# 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)]))
# }