Mercurial > matrix-functions
comparison toolbox/seqcheb.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 x = seqcheb(n, k) | |
2 %SEQCHEB Sequence of points related to Chebyshev polynomials. | |
3 % X = SEQCHEB(N, K) produces a row vector of length N. | |
4 % There are two choices: | |
5 % K = 1: zeros of T_N, (the default) | |
6 % K = 2: extrema of T_{N-1}, | |
7 % where T_k is the Chebsyhev polynomial of degree k. | |
8 | |
9 if nargin == 1, k = 1; end | |
10 | |
11 if k == 1 % Zeros of T_n | |
12 i = 1:n; j = .5*ones(1,n); | |
13 x = cos( (i-j) * (pi/n) ); | |
14 elseif k == 2 % Extrema of T_(n-1) | |
15 i = 0:n-1; | |
16 x = cos( i * (pi/(n-1)) ); | |
17 end |