R: Vectorize a matrix

vech {matrixcalc} | R Documentation

## Vectorize a matrix

### Description

This function returns a stack of the lower triangular matrix of a square matrix as a matrix with 1 column and n * ( n + 1 ) / 2 rows

### Usage

    vech(x)

### Arguments

`x` | a matrix

### Value

A matrix with \frac{1}{2}n≤ft( {n + 1} \right) rows and one column.

### Author(s)

Frederick Novomestky fnovomes@poly.edu

### References

Magnus, J. R. and H. Neudecker (1999) Matrix Differential Calculus with Applications in Statistics and Econometrics, Second Edition, John Wiley.

### See Also

`is.square.matrix`

### Examples

    x <- matrix( seq( 1, 16, 1 ), nrow=4, byrow=TRUE )
    print( x )
    y <- vech( x )
    print( y )

[Package matrixcalc version 1.0-3 Index]