Function File: zi = griddata_prepared (x, y, z, xi, yi, tri)
: zi = griddata_prepared (x, y, z, xi, yi, tri, method)
: [xi, yi, zi] = griddata_prepared (…)

This is an optimized variant of Octave’s builtin griddata function where the triangulation has to be performed only once.

tri … triangulation data returned from delaunay

See also: griddata, delaunay.

Demonstration 1

The following code

 x = linspace(-pi, pi, 10);
 y = linspace(-pi, pi, 15);
 [xx, yy] = meshgrid(x, y);
 tri = delaunay(xx, yy);
 zz = sin(xx.^2 + yy.^2) ./ (xx.^2 + yy.^2);
 xi = 2 * pi * (2 * rand(1, 5) - 1);
 yi = 2 * pi * (2 * rand(1, 7) - 1);
 tri = delaunay(xx, yy);
 zi = zeros(numel(xi), numel(yi));
 for i=1:numel(xi)
   for j=1:numel(yi)
     zi(i, j) = griddata_prepared(xx, yy, zz, xi(i), yi(j), tri, "linear/nearest");
   endfor
 endfor

gives an example of how 'griddata_prepared' is used.

Package: mboct-octave-pkg