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annotate toolbox/seqcheb.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
parents 8f23314345f4
children
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8f23314345f4 Create local repository for matrix toolboxes. Step #0 done.
Antonio Pino Robles <data.script93@gmail.com>
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1 function x = seqcheb(n, k)
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2 %SEQCHEB Sequence of points related to Chebyshev polynomials.
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3 % X = SEQCHEB(N, K) produces a row vector of length N.
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4 % There are two choices:
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5 % K = 1: zeros of T_N, (the default)
8f23314345f4 Create local repository for matrix toolboxes. Step #0 done.
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6 % K = 2: extrema of T_{N-1},
8f23314345f4 Create local repository for matrix toolboxes. Step #0 done.
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7 % where T_k is the Chebsyhev polynomial of degree k.
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8
8f23314345f4 Create local repository for matrix toolboxes. Step #0 done.
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9 if nargin == 1, k = 1; end
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8f23314345f4 Create local repository for matrix toolboxes. Step #0 done.
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11 if k == 1 % Zeros of T_n
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12 i = 1:n; j = .5*ones(1,n);
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13 x = cos( (i-j) * (pi/n) );
8f23314345f4 Create local repository for matrix toolboxes. Step #0 done.
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14 elseif k == 2 % Extrema of T_(n-1)
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15 i = 0:n-1;
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16 x = cos( i * (pi/(n-1)) );
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17 end