R.utils (version 0.9.8)

arrayIndex: Converts vector indices to array indices

Usage

## S3 method for class 'default}(i, dim, ...)':
arrayIndexundefined

Converts vector indices to array indices assuming last array dimension to "move fastest", e.g.
 matrices are stored column by column.

i{A vector of vector indices to be converted to array
   indices.}
 dim{A non-empty numeric vector specifying the dimension of
   the array.}
 ...{Not used.}

Returns a numeric matrix of length(i) rows and
 length(dim) columns.

# 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)))

[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.

which() with argument arr.ind=TRUE.



manip
utilities

Arguments