interp, a FORTRAN77 code which takes a set of data associated with successive values of a parameter, and produces an interpolating function which can be evaluated over a continuous range of the parameter.
The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.
interp is available in a C version and a C++ version and a Fortran90 version and a MATLAB version and an Octave version.
bernstein_polynomial, a FORTRAN77 library which evaluates the Bernstein polynomials, useful for uniform approximation of functions;
divdif, a FORTRAN77 library which uses divided differences to interpolate data.
hermite, a FORTRAN77 library which computes the Hermite interpolant, a polynomial that matches function values and derivatives.
NMS, a FORTRAN77 library which includes a package for the computation of piecewise cubic Hermite splines.
PPPACK, a FORTRAN77 library which implements Carl de Boor's piecewise polynomial functions, including, in particular, cubic splines.
RBF_INTERP, a FORTRAN77 library which defines and evaluates radial basis interpolants to multidimensional data.
SPLINE, a FORTRAN77 library which computes functions that approximate or interpolate data.
TEST_APPROX, a FORTRAN77 library which defines a number of test problems for approximation and interpolation.
TEST_INTERP_1D, a FORTRAN77 library which defines test problems for interpolation of data y(x), depending on a 1D argument.