R: Vectorization the lower triangular part of a square matrix

vech {fastmatrix} | R Documentation

## Vectorization the lower triangular part of a square matrix

### Description

This function returns a vector obtained by stacking the lower triangular part of a square matrix.

### Usage

    vech(x)

### Arguments

`x` | a square matrix.

### Value

Let `x` be a n by n matrix, then `vech(x)` is a n(n+1)/2-dimensional vector.

### Examples

    x <- matrix(rep(1:10, each = 10), ncol = 10)
    x
    y <- vech(x)
    y

[Package fastmatrix version 0.2-3571 Index]