Row Indexes

Usage

row(x, as.factor=FALSE)

Arguments

x a matrix.
as.factor a logical value indicating whether the value should be returned as a factor rather than as numeric.

Value

An integer matrix with the same dimensions as x and whose ij-th element is equal to i.

See Also

col to get columns.

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,nr=5,nc=5)
x[row(x)==col(x)] <- 1
x

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