# lower_tri: Return a triangular matrix In mclark--/lazerhawk: Miscellaneous functions mostly inspired by synthwave

## Description

Returns the upper or lower triangle of a matrix.

## Usage

 ```1 2 3 4 5 6 7``` ```lower_tri(x, diag = FALSE, valuesOnly = FALSE, otherVal = 0) lowerTri(x, diag = FALSE, valuesOnly = FALSE, otherVal = 0) upper_tri(x, diag = FALSE, valuesOnly = FALSE, otherVal = 0) upperTri(x, diag = FALSE, valuesOnly = FALSE, otherVal = 0) ```

## Arguments

 `x` A matrix `diag` logical. Include the diagonal? Default is false. `valuesOnly` logical. Return only the lower/upper triangle values (including diag argument) `otherVal` numeric or NA. what to make nonlower/upper values. `0` by default.

## Details

This function returns the lower/upper triangle of a square matrix rather than just its indices (e.g. as lower.tri does). `otherVal` is only relevant if `valuesOnly` is `FALSE`.

## Value

A lower or upper triangular matrix, possibly with diagonal. If `valuesOnly` is `TRUE`, then only the vector of values are returned.

`lower.tri`, `diag`, `matrix`

## Examples

 ```1 2 3 4 5 6 7``` ```library(lazerhawk) (m <- matrix(1:9, 3, 3, byrow=TRUE)) lower.tri(m) lower_tri(m) lower_tri(m, diag=TRUE, otherVal=NA) lower_tri(m, valuesOnly=TRUE) upper_tri(m, diag=TRUE, otherVal=NA) ```

mclark--/lazerhawk documentation built on July 17, 2018, 3:11 a.m.