chebyshev Evaluate a Chebyshev polynomial of the first kind. Uses Clenshaw's algorithm.
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Chebyshev polynomials.
A Chebyshev polynomial of the first kind is defined by the following recurrence:
\begin{aligned}
T_0(x) &= 1 \\
T_1(x) &= x \\
T_{n+1}(x) &= 2xT_n(x) - T_{n-1}(x) \\
\end{aligned}
chebyshev Evaluate a Chebyshev polynomial of the first kind. Uses Clenshaw's algorithm.
chebyshevBroucke Evaluate a Chebyshev polynomial of the first kind. Uses Broucke's ECHEB algorithm, and his convention for coefficient handling. It treat 0th coefficient different so
chebyshev x [a0,a1,a2...] == chebyshevBroucke [2*a0,a1,a2...]Broucke, R. (1973) Algorithm 446: Ten subroutines for the manipulation of Chebyshev series. Communications of the ACM 16(4):254–256. http://doi.acm.org/10.1145/362003.362037
Clenshaw, C.W. (1962) Chebyshev series for mathematical functions. National Physical Laboratory Mathematical Tables 5, Her Majesty's Stationery Office, London.