padua


padua, an Octave code which returns the coordinates of the 2D Padua points, as well as interpolation weights or quadrature weights, and images of the points in MATLAB graphics files.

Licensing:

The computer code and data files made available on this web page are distributed under the MIT license

Languages:

padua is available in a C version and a C++ version and a Fortran90 version and a MATLAB version and an Octave version and a Python version.

Related Data and Programs:

padua_test

lagrange_interp_2d, an Octave code 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, an Octave code which evaluates a piecewise linear interpolant to data defined on a regular 2D grid.

quadrature_weights_vandermonde_2d, an Octave code which computes the weights of a 2D quadrature rule using the Vandermonde matrix, assuming that the points have been specified.

rbf_interp_2d, an Octave code which defines and evaluates radial basis function (RBF) interpolants to 2D data.

shepard_interp_2d, an Octave code which defines and evaluates Shepard interpolants to 2D data, based on inverse distance weighting.

test_interp_2d, an Octave code which defines test problems for interpolation of data z(x,y), depending on a 2D argument.

toms886, an Octave code which defines the Padua points for interpolation in a 2D region, including the rectangle, triangle, and ellipse, by Marco Caliari, Stefano de Marchi, Marco Vianello. This is ACM TOMS algorithm 886.

vandermonde_interp_2d, an Octave code 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. Marco Caliari, Stefano de Marchi, Marco Vianello,
    Bivariate interpolation on the square at new nodal sets,
    Applied Mathematics and Computation,
    Volume 165, Number 2, 2005, pages 261-274.
  2. Marco Caliari, Stefano de Marchi, Marco Vianello,
    Algorithm 886: Padua2D: Lagrange Interpolation at Padua Points on Bivariate Domains,
    ACM Transactions on Mathematical Software,
    Volume 35, Number 3, October 2008, Article 21, 11 pages.

Source Code:


Last revised on 11 June 2023.