NEWTON_INTERP_1D, a MATLAB 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 MATLAB 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 MATLAB library which determines the combination of Chebyshev polynomials which interpolates a set of data, so that p(x(i)) = y(i).
DIVDIF, a MATLAB library which uses divided differences to compute the polynomial interpolant to a given set of data.
HERMITE, a MATLAB library which computes the Hermite interpolant, a polynomial that matches function values and derivatives.
LAGRANGE_INTERP_1D, a MATLAB 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 MATLAB library which interpolates a set of data using a piecewise constant interpolant defined by the nearest neighbor criterion.
PWL_INTERP_1D, a MATLAB library which interpolates a set of data using a piecewise linear interpolant.
R8LIB, a MATLAB library which contains many utility routines, using double precision real (R8) arithmetic.
RBF_INTERP_1D, a MATLAB library which defines and evaluates radial basis function (RBF) interpolants to 1D data.
SHEPARD_INTERP_1D, a MATLAB library which defines and evaluates Shepard interpolants to 1D data, which are based on inverse distance weighting.
SPLINE, a MATLAB library which constructs and evaluates spline interpolants and approximants.
TEST_INTERP_1D, a MATLAB library which defines test problems for interpolation of data y(x), depending on a 2D argument.
VANDERMONDE_INTERP_1D, a MATLAB 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 test code requires the test_interp library as well. If this library is available in a separate folder at the same "level" as this library, then a Matlab command such as "addpath ( '../test_interp')" will make that library accessible for a run of the test program.
The code generates some plots of the data and approximants.
You can go up one level to the MATLAB source codes.