# gallery

## Purpose

Small test matrices.

## Synopsis

    X = gallery(3)
    X = gallery(5)

## Description

`X = gallery(3)` returns a badly conditioned 3-by-3 matrix.

`X = gallery(5)` returns a 5-by-5 matrix that poses an interesting eigenvalue problem. Using exact arithmetic, `gallery(5)` has a single eigenvalue at zero with algebraic multiplicity 5; and a single eigenvector. Numerical calculations, however, yield five distinct eigenvalues: two pairs of complex eigenvalues and a real eigenvalue.

For any input other than 3 or 5, `gallery` returns an empty matrix.

## See Also

    hadamard, hilb, invhilb, magic, rosser, wilkinson

(c) Copyright 1994 by The MathWorks, Inc.