TOMS886 is a FORTRAN90 library which implements an interpolation procedure based on "Padua points", defined in the square [-1,+1]^2, whose interpolating power is especially good. It is possible to map these points to the general rectangle, ellipse or triangle to do interpolation on these regions as well.
The original, true, correct version of ACM TOMS Algorithm 886 is available through ACM: http://www.acm.org/pubs/calgo or NETLIB: http://www.netlib.org/toms/index.html.
The computer code and data files made available on this web page are distributed under the GNU LGPL license.
TOMS886 is available in a C version and a C++ version and a FORTRAN77 version and a FORTRAN90 version and a MATLAB version.
LAGRANGE_INTERP_2D, a FORTRAN77 library which defines and evaluates the Lagrange polynomial p(x,y) which interpolates a set of data depending on a 2D argument that was evaluated on a product grid, so that p(x(i),y(j)) = z(i,j).
PADUA, a FORTRAN90 library which returns the points and weights for Padu sets, useful for interpolation in 2D. GNUPLOT is used to plot the points.
PWL_INTERP_2D, a FORTRAN90 library which evaluates a piecewise linear interpolant to data defined on a regular 2D grid.
PWL_INTERP_2D_SCATTERED, a FORTRAN90 library which evaluates a piecewise linear interpolant to data which is available at an irregularly arranged set of points.
RBF_INTERP_2D, a FORTRAN90 library which defines and evaluates radial basis function (RBF) interpolants to 2D data.
SHEPARD_INTERP_2D, a FORTRAN90 library which defines and evaluates Shepard interpolants to scattered 2D data, based on inverse distance weighting.
TEST_INTERP_2D, a FORTRAN90 library which defines test problems for interpolation of regular or scattered data z(x,y), depending on a 2D argument.
TOMS526, a FORTRAN90 library which interpolates scattered bivariate data. This is ACM TOMS algorithm 526, by Hiroshi Akima;
TOMS660, a FORTRAN90 library which takes scattered 2D data and produces an interpolating function F(X,Y). This is ACM TOMS algorithm 660, called qshep2d, by Robert Renka.
TOMS790, a FORTRAN90 library which computes an interpolating function to a set of scattered data in the plane, by Robert Renka; This library is commonly called cshep2d; this is ACM TOMS algorithm 790.
TOMS792, a FORTRAN90 library which tests functions that interpolate scattered data in the plane; by Robert Renka; this is ACM TOMS algorithm 792.
VANDERMONDE_INTERP_2D, a FORTRAN90 library which finds a polynomial interpolant to data z(x,y) of a 2D argument by setting up and solving a linear system for the polynomial coefficients, involving the Vandermonde matrix.
Marco Caliari, Stefano de Marchi, Marco Vianello.
ELLIPSE applies the procedure to an ellipse.
RECTANGLE applies the procedure to a rectangle.
TRIANGLE applies the procedure to a triangle.
You can go up one level to the FORTRAN90 source codes.