1 ## Copyright (C) 2007-2012 David Bateman
3 ## This file is part of Octave.
5 ## Octave is free software; you can redistribute it and/or modify it
6 ## under the terms of the GNU General Public License as published by
7 ## the Free Software Foundation; either version 3 of the License, or (at
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13 ## General Public License for more details.
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20 ## @deftypefn {Function File} {@var{vi} =} griddata3 (@var{x}, @var{y}, @var{z}, @var{v}, @var{xi}, @var{yi}, @var{zi}, @var{method}, @var{options})
22 ## Generate a regular mesh from irregular data using interpolation.
23 ## The function is defined by @code{@var{v} = f (@var{x}, @var{y}, @var{z})}.
24 ## The interpolation points are specified by @var{xi}, @var{yi}, @var{zi}.
26 ## The interpolation method can be @code{"nearest"} or @code{"linear"}.
27 ## If method is omitted it defaults to @code{"linear"}.
28 ## @seealso{griddata, griddatan, delaunayn}
31 ## Author: David Bateman <dbateman@free.fr>
33 function vi = griddata3 (x, y, z, v, xi, yi, zi, method, varargin)
39 if (!all (size (x) == size (y) & size (x) == size(z) & size(x) == size (v)))
40 error ("griddata3: X, Y, Z, and V must be vectors of same length");
43 ## meshgrid xi, yi and zi if they are vectors unless they
44 ## are vectors of the same length
45 if (isvector (xi) && isvector (yi) && isvector (zi)
46 && (numel (xi) != numel (yi) || numel (xi) != numel (zi)))
47 [xi, yi, zi] = meshgrid (xi, yi, zi);
50 if (any (size(xi) != size(yi)) || any (size(xi) != size(zi)))
51 error ("griddata3: XI, YI and ZI must be vectors or matrices of same size");
54 vi = griddatan ([x(:), y(:), z(:)], v(:), [xi(:), yi(:), zi(:)], varargin{:});
55 vi = reshape (vi, size (xi));
61 %! old_state = rand ("state");
62 %! restore_state = onCleanup (@() rand ("state", old_state));
64 %! x = 2 * rand (1000, 1) - 1;
65 %! y = 2 * rand (1000, 1) - 1;
66 %! z = 2 * rand (1000, 1) - 1;
67 %! v = x.^2 + y.^2 + z.^2;
68 %! [xi, yi, zi] = meshgrid (-0.8:0.2:0.8);
69 %! vi = griddata3 (x, y, z, v, xi, yi, zi, 'linear');
70 %! vv = vi - xi.^2 - yi.^2 - zi.^2;
71 %! assert (max (abs (vv(:))), 0, 0.1);
74 %! old_state = rand ("state");
75 %! restore_state = onCleanup (@() rand ("state", old_state));
77 %! x = 2 * rand (1000, 1) - 1;
78 %! y = 2 * rand (1000, 1) - 1;
79 %! z = 2 * rand (1000, 1) - 1;
80 %! v = x.^2 + y.^2 + z.^2;
81 %! [xi, yi, zi] = meshgrid (-0.8:0.2:0.8);
82 %! vi = griddata3 (x, y, z, v, xi, yi, zi, 'nearest');
83 %! vv = vi - xi.^2 - yi.^2 - zi.^2;
84 %! assert (max (abs (vv(:))), 0, 0.1)