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).
The code needs the QR_SOLVE and R8LIB libraries. The test program needs the TEST_INTERP library.
The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.
chebyshev_interp_1d is available in a C version and a C++ version and a Fortran90 version and a MATLAB version and an Octave version and a Python version.
barycentric_interp_1d, a FORTRAN77 library which defines and evaluates the barycentric Lagrange polynomial p(x) which interpolates a set of data, so that p(x(i)) = y(i). The barycentric approach means that very high degree polynomials can safely be used.
chebyshev, a FORTRAN77 library which computes the Chebyshev interpolant/approximant to a given function over an interval.
chebyshev_series, a FORTRAN77 library 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.
DIVDIF, a FORTRAN77 library which uses divided differences to compute the polynomial interpolant to a given set of data.
HERMITE, a FORTRAN77 library which computes the Hermite interpolant, a polynomial that matches function values and derivatives.
LAGRANGE_INTERP_1D, a FORTRAN77 library which defines and evaluates the Lagrange polynomial p(x) which interpolates a set of data, so that p(x(i)) = y(i).
NEAREST_INTERP_1D, a FORTRAN77 library which interpolates a set of data using a piecewise constant interpolant defined by the nearest neighbor criterion.
PWL_INTERP_1D, a FORTRAN77 library which interpolates a set of data using a piecewise linear interpolant.
QR_SOLVE, a FORTRAN77 library which computes the least squares solution of a linear system A*x=b.
R8LIB, a FORTRAN77 library which contains many utility routines using double precision real (R8) arithmetic.
RBF_INTERP_1D, a FORTRAN77 library which defines and evaluates radial basis function (RBF) interpolants to 1D data.
SHEPARD_INTERP_1D, a FORTRAN77 library which defines and evaluates Shepard interpolants to 1D data, based on inverse distance weighting.
SPLINE, a FORTRAN77 library which constructs and evaluates spline interpolants and approximants.
TEST_INTERP, a FORTRAN77 library which defines a number of test problems for interpolation, provided as a set of (x,y) data.
TEST_INTERP_1D, a FORTRAN77 library which defines test problems for interpolation of data y(x), depending on a 2D argument.
VANDERMONDE_INTERP_1D, a FORTRAN77 library which finds a polynomial interpolant to data y(x) of a 1D argument, by setting up and solving a linear system for the polynomial coefficients, involving the Vandermonde matrix.