Upper Triangular Matrix Test

Determine if a matrix is upper triangular.

Usage

is.triu(x)

Arguments

x

A matrix.

Value

Logical indicating whether the given matrix is lower triangular.

Examples

m <- mat("1, -1, -1, -1; 0, 1, -2, -2; 0, 0, 1, -3; 0, 0, 0, 1")
is.triu(m)
#> [1] TRUE
is.triu(eye(3, 5))
#> [1] TRUE