# orth

## Purpose

Range space of a matrix.

## Synopsis

    Q = orth(X)

## Description

`Q = orth(X)` returns an orthonormal basis for the range of `X`. The columns of `Q` span the same space as the columns of `X`, and the columns of `Q` are orthogonal, so that

    Q'*Q = eye(min(size(X)))

The number of columns of `Q` is the rank of `X`.

## See Also

`null`, `qr`

(c) Copyright 1994 by The MathWorks, Inc.