W = wilkinson(n)
wilkinson(n)
is one of J. H. Wilkinson's eigenvalue test matrices. It is a symmetric, tridiagonal matrix with pairs of nearly, but not exactly, equal eigenvalues.
wilkinson(7)
is
The most frequently used case is3 1 0 0 0 0 0
1 2 1 0 0 0 0
0 1 1 1 0 0 0
0 0 1 0 1 0 0
0 0 0 1 1 1 0
0 0 0 0 1 2 1
0 0 0 0 0 1 3
wilkinson(21)
. Its two largest eigenvalues are both about 10.746; they agree to 14, but not to 15, decimal places.
eig
,pascal
,rosser
(c) Copyright 1994 by The MathWorks, Inc.