clausen, a Fortran77 code which evaluates a Chebyshev interpolant to the Clausen function Cl2(x).
Cl2(x) = - integral ( 0 < s < x ) log ( abs ( 2 sin ( x / 2 ) ) ) dx
The Clausen function is periodic, with period 2 pi.
The information on this web page is distributed under the MIT license.
clausen is available in a C version and a C++ version and a Fortran77 version and a Fortran90 version and a MATLAB version and an Octave version and a Python version.
chebyshev, a Fortran77 code which computes the Chebyshev interpolant/approximant to a given function over an interval.
chebyshev_interp_1d, a Fortran77 code which determines the combination of Chebyshev polynomials which interpolates a set of data, so that p(x(i)) = y(i).
chebyshev_polynomial, a Fortran77 code which considers the Chebyshev polynomials T(i,x), U(i,x), V(i,x) and W(i,x). Functions are provided to evaluate the polynomials, determine their zeros, produce their polynomial coefficients, produce related quadrature rules, project other functions onto these polynomial bases, and integrate double and triple products of the polynomials.
chebyshev_series, a Fortran77 code which can evaluate a Chebyshev series approximating a function f(x), while efficiently computing one, two or three derivatives of the series, which approximate f'(x), f''(x), and f'''(x), by Manfred Zimmer.
fn, a Fortran77 code which approximates elementary and special functions using Chebyshev polynomials; functions include Airy, Bessel I, J, K and Y, beta, confluent hypergeometric, error, gamma, log gamma, Pochhammer, Spence; integrals include hyperbolic cosine, cosine, Dawson, exponential, logarithmic, hyperbolic sine, sine; by Wayne Fullerton.
polpak, a Fortran77 code which evaluates a variety of mathematical functions, including Chebyshev, Gegenbauer, Hermite, Jacobi, Laguerre, Legendre polynomials, and the Collatz sequence.
test_values, a Fortran77 code which supplies test values of various mathematical functions.
toms446, a Fortran77 code which manipulates Chebyshev series for interpolation and approximation; this is ACM TOMS algorithm 446, by Roger Broucke.