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annotate toolbox/moler.m @ 2:c124219d7bfa draft

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Re-add the 1995 toolbox after noticing the statement in the ~higham/mctoolbox/ webpage.
author Antonio Pino Robles <data.script93@gmail.com>
date Thu, 07 May 2015 18:36:24 +0200
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Antonio Pino Robles <data.script93@gmail.com>
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1 function A = moler(n, alpha)
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2 %MOLER Moler matrix - symmetric positive definite.
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3 % A = MOLER(N, ALPHA) is the symmetric positive definite N-by-N matrix
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4 % U'*U where U = TRIW(N, ALPHA).
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5 % For ALPHA = -1 (the default) A(i,j) = MIN(i,j)-2, A(i,i) = i.
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6 % A has one small eigenvalue.
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8 % Nash (1990) attributes the ALPHA = -1 matrix to Moler.
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9 %
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10 % Reference:
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11 % J.C. Nash, Compact Numerical Methods for Computers: Linear
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12 % Algebra and Function Minimisation, second edition, Adam Hilger,
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13 % Bristol, 1990 (Appendix 1).
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15 if nargin == 1, alpha = -1; end
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8f23314345f4 Create local repository for matrix toolboxes. Step #0 done.
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17 A = triw(n, alpha)'*triw(n, alpha);