R: Find the trace of a square matrix

tr {psych} | R Documentation

## Find the trace of a square matrix

### Description

Hardly worth coding, if it didn't appear in so many formulae in psychometrics, the trace of a (square) matrix is just the sum of the diagonal elements.

### Usage

    tr(m)

### Arguments

`m` | A square matrix

### Details

The tr function is used in various matrix operations and is the sum of the diagonal elements of a matrix.

### Value

The sum of the diagonal elements of a square matrix.
i.e. tr(m) <- sum(diag(m)).

### Examples

     m <- matrix(1:16,ncol=4)
     m
     tr(m)

[Package psych version 1.7.3.21 Index]