is.lower.tri

Check if a matrix is lower or upper triangular

Description

Returns TRUE if the given matrix is lower or upper triangular matrix.

Usage

is.lower.tri(x, diag = FALSE)
is.upper.tri(x, diag = FALSE)

Arguments

Argument	Description
x	a matrix of other list() object with length(dim(x)) == 2 .
diag	logical. Should the diagonal be included?

Value

Check if a matrix is lower or upper triangular. You can also include diagonal to the check.

Seealso

lower.tri , upper.tri

Examples

x <- matrix(rnorm(10 * 3), ncol = 3)
R <- chol(crossprod(x))

is.lower.tri(R)
is.upper.tri(R)