SHEPARD_INTERP_2D
Shepard Interpolation of 2D Data


SHEPARD_INTERP_2D is a MATLAB library which defines and evaluates Shepard interpolants to 2D data, based on inverse distance weighting.

SHEPARD_INTERP_2D needs the R8LIB library. The test also needs the TEST_INTERP_2D library.

Licensing:

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Languages:

SHEPARD_INTERP_2D is available in a C version and a C++ version and a FORTRAN77 version and a FORTRAN90 version and a MATLAB version.

Related Data and Programs:

LAGRANGE_INTERP_2D, a MATLAB 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).

PWL_INTERP_2D, a MATLAB library which evaluates a piecewise linear interpolant to data defined on a regular 2D grid.

R8LIB, a MATLAB library which contains many utility routines using double precision real (R8) arithmetic.

RBF_INTERP_2D, a MATLAB library which defines and evaluates radial basis function (RBF) interpolants to 2D data.

SHEPARD_INTERP_1D, a MATLAB library which defines and evaluates Shepard interpolants to 1D data, based on inverse distance weighting.

SHEPARD_INTERP_ND, a MATLAB library which defines and evaluates Shepard interpolants to multidimensional data, based on inverse distance weighting.

TEST_INTERP_2D, a MATLAB library which defines test problems for interpolation of data z(x,y)), depending on a 2D argument.

VANDERMONDE_INTERP_2D, a MATLAB 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.

Reference:

  1. Richard Franke,
    Scattered Data Interpolation: Tests of Some Methods,
    Mathematics of Computation,
    Volume 38, Number 157, January 1982, pages 181-200.
  2. Donald Shepard,
    A two-dimensional interpolation function for irregularly spaced data,
    ACM '68: Proceedings of the 1968 23rd ACM National Conference,
    ACM, pages 517-524, 1969.

Source Code:

Examples and Tests:

Running these tests requires access to the test_interp_2d library. Should that library be available in a directory at the same level, this can be accomplished with the command "addpath ( '../test_interp_2d' )".

The code generates some plots of the data and approximants.

You can go up one level to the MATLAB source codes.


Last modified on 04 August 2012.