tr {tensr}

Trace of a matrix.

Description

Returns the sum of the diagonal elements of a matrix.

Usage

tr(X)

Arguments

X

A matrix whose diagonal elements will be added together.

Details

This returns the trace of a matrix, which is just the sum of its diagonal elements.

Value

The sum of the diagonal elements of X.

Author(s)

Peter Hoff.

Examples

X <- matrix(1:4, nrow = 2, ncol = 2)
X
tr(X)