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## Copyright (C) 2007 Muthiah Annamalai <muthiah.annamalai@uta.edu>
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## This program is free software; you can redistribute it and/or modify it under
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## the terms of the GNU General Public License as published by the Free Software
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## Foundation; either version 3 of the License, or (at your option) any later
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## This program is distributed in the hope that it will be useful, but WITHOUT
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## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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## FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
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## You should have received a copy of the GNU General Public License along with
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## this program; if not, see <http://www.gnu.org/licenses/>.
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## @deftypefn {Function File} {@var{coefs}=} chebyshevpoly (@var{kind},@var{order},@var{x})
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## Compute the coefficients of the Chebyshev polynomial, given the
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## @var{order}. We calculate the Chebyshev polynomial using the recurrence
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## relations, Tn+1(x) = (2*x*Tn(x) - Tn-1(x)). The @var{kind} can set to
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## compute the first or second kind chebyshev polynomial.
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## If the value @var{x} is specified, the polynomial is also evaluated,
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## otherwise just the return the coefficients of the polynomial are returned.
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## This is NOT the generalized Chebyshev polynomial.
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function h=chebyshevpoly(kind,order,val)
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if nargin < 2, print_usage, endif
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error('unknown kind');
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if (length(h_now) < (1+ord))
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y=zeros(1,(1+ord)-length(h_prev));