Mercurial > matrix-functions
comparison toolbox/forsythe.m @ 2:c124219d7bfa draft
Re-add the 1995 toolbox after noticing the statement in the ~higham/mctoolbox/ webpage.
author | Antonio Pino Robles <data.script93@gmail.com> |
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date | Thu, 07 May 2015 18:36:24 +0200 |
parents | 8f23314345f4 |
children |
comparison
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1:e471a92d17be | 2:c124219d7bfa |
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1 function A = forsythe(n, alpha, lambda) | |
2 %FORSYTHE Forsythe matrix - a perturbed Jordan block. | |
3 % FORSYTHE(N, ALPHA, LAMBDA) is the N-by-N matrix equal to | |
4 % JORDBLOC(N, LAMBDA) except it has an ALPHA in the (N,1) position. | |
5 % It has the characteristic polynomial | |
6 % DET(A-t*EYE) = (LAMBDA-t)^N - (-1)^N ALPHA. | |
7 % ALPHA defaults to SQRT(EPS) and LAMBDA to 0. | |
8 | |
9 if nargin < 2, alpha = sqrt(eps); end | |
10 if nargin < 3, lambda = 0; end | |
11 | |
12 A = jordbloc(n, lambda); | |
13 A(n,1) = alpha; |