### Name: row
### Title: Row Indexes
### Aliases: row
### Keywords: array

### ** Examples

x <- matrix(1:12, 3, 4)
# extract the diagonal of a matrix
dx <- x[row(x) == col(x)]
dx

# create an identity 5-by-5 matrix
x <- matrix(0, nrow = 5, ncol = 5)
x[row(x) == col(x)] <- 1
x