arrayIndex {R.utils} | R Documentation |
Converts vector indices to array indices assuming last array dimension to "move fastest", e.g. matrices are stored column by column.
## Default S3 method: arrayIndex(i, dim, ...)
i |
A |
dim |
A non-empty |
... |
Not used. |
Returns an integer
matrix
of length(i)
rows and
length(dim)
columns.
[1] H. Bengtsson, Bayesian Networks - a self-contained
introduction with implementation remarks, Master's Thesis in
Computer Science, Mathematical Statistics, Lund Institute of
Technology, 1999.
From R v2.11.0 there is arrayInd
(), which does
the same thing as this method.
which
() with argument arr.ind=TRUE
.
# Single index print(arrayIndex(21, dim=c(4,3,3))) # Multiple indices print(arrayIndex(20:23, dim=c(4,3,3))) # Whole array x <- array(1:30, dim=c(5,6)) print(arrayIndex(1:length(x), dim=dim(x))) # Find (row,column) of maximum value m <- diag(4-abs(-4:4)) print(arrayIndex(which.max(m), dim=dim(m)))