NEWTON_INTERP_1D, a FORTRAN90 library which finds a polynomial interpolant to data using Newton divided differences.
NEWTON_INTERP_1D needs access to the R8LIB libraries. The test code also needs access to 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.
NEWTON_INTERP_1D is available in a C version and a C++ version and a FORTRAN77 version and a FORTRAN90 version and a MATLAB version and a Python version.
BARYCENTRIC_INTERP_1D, a FORTRAN90 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_INTERP_1D, a FORTRAN90 library which determines the combination of Chebyshev polynomials which interpolates a set of data, so that p(x(i)) = y(i).
DIVDIF, a FORTRAN90 library which uses divided differences to compute the polynomial interpolant to a given set of data.
HERMITE, a FORTRAN90 library which computes the Hermite interpolant, a polynomial that matches function values and derivatives.
LAGRANGE_INTERP_1D, a FORTRAN90 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 FORTRAN90 library which interpolates a set of data using a piecewise constant interpolant defined by the nearest neighbor criterion.
PWL_INTERP_1D, a FORTRAN90 library which interpolates a set of data using a piecewise linear interpolant.
R8LIB, a FORTRAN90 library which contains many utility routines, using double precision real (R8) arithmetic.
RBF_INTERP_1D, a FORTRAN90 library which defines and evaluates radial basis function (RBF) interpolants to 1D data.
SHEPARD_INTERP_1D, a FORTRAN90 library which defines and evaluates Shepard interpolants to 1D data, which are based on inverse distance weighting.
SPLINE, a FORTRAN90 library which constructs and evaluates spline interpolants and approximants.
TEST_INTERP_1D, a FORTRAN90 library which defines test problems for interpolation of data y(x), depending on a 2D argument.
VANDERMONDE_INTERP_1D, a FORTRAN90 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.
The code generates some plots of the data and approximants.
You can go up one level to the FORTRAN90 source codes.