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comparison toolbox/forsythe.m @ 0:8f23314345f4 draft

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Create local repository for matrix toolboxes. Step #0 done.
author Antonio Pino Robles <data.script93@gmail.com>
date Wed, 06 May 2015 14:56:53 +0200
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-1:000000000000 0:8f23314345f4
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;