R: Check if a matrix is lower or upper triangular

is.lower.tri {fastmatrix} | R Documentation

## 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

`x` | a matrix of other R 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.

### See Also

`lower.tri`, `upper.tri`

### Examples

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

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

[Package fastmatrix version 0.3-8196 Index]