octave: scripts/geometry/griddata.m annotate

annotate scripts/geometry/griddata.m @ 14138:72c96de7a403 stable

maint: update copyright notices for 2012

author	John W. Eaton <jwe@octave.org>
date	Mon, 02 Jan 2012 14:25:41 -0500
parents	d5bd2766c640
children	11949c9795a0

rev	line source
14138 72c96de7a403 maint: update copyright notices for 2012 John W. Eaton <jwe@octave.org> parents: 11588 diff changeset	1 ## Copyright (C) 1999-2012 Kai Habel
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	2 ##
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	3 ## This file is part of Octave.
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	4 ##
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	5 ## Octave is free software; you can redistribute it and/or modify it
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	6 ## under the terms of the GNU General Public License as published by
7016 93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe] jwe parents: 6826 diff changeset	7 ## the Free Software Foundation; either version 3 of the License, or (at
93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe] jwe parents: 6826 diff changeset	8 ## your option) any later version.
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	9 ##
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	10 ## Octave is distributed in the hope that it will be useful, but
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	11 ## WITHOUT ANY WARRANTY; without even the implied warranty of
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	12 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	13 ## General Public License for more details.
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	14 ##
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	15 ## You should have received a copy of the GNU General Public License
7016 93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe] jwe parents: 6826 diff changeset	16 ## along with Octave; see the file COPYING. If not, see
93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe] jwe parents: 6826 diff changeset	17 ## <http://www.gnu.org/licenses/>.
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	18
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	19 ## -- texinfo --
10793 be55736a0783 Grammarcheck the documentation from m-files. Rik <octave@nomad.inbox5.com> parents: 10549 diff changeset	20 ## @deftypefn {Function File} {@var{zi} =} griddata (@var{x}, @var{y}, @var{z}, @var{xi}, @var{yi}, @var{method})
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	21 ## @deftypefnx {Function File} {[@var{xi}, @var{yi}, @var{zi}] =} griddata (@var{x}, @var{y}, @var{z}, @var{xi}, @var{yi}, @var{method})
10945 aa40bdbfa478 griddata.m: Allow x, y inputs to be vectors, and z a matrix. Ben Abbott <bpabbott@mac.com> parents: 10793 diff changeset	22 ##
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	23 ## Generate a regular mesh from irregular data using interpolation.
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	24 ## The function is defined by @code{@var{z} = f (@var{x}, @var{y})}.
10945 aa40bdbfa478 griddata.m: Allow x, y inputs to be vectors, and z a matrix. Ben Abbott <bpabbott@mac.com> parents: 10793 diff changeset	25 ## Inputs @code{@var{x}, @var{y}, @var{z}} are vectors of the same length
aa40bdbfa478 griddata.m: Allow x, y inputs to be vectors, and z a matrix. Ben Abbott <bpabbott@mac.com> parents: 10793 diff changeset	26 ## or @code{@var{x}, @var{y}} are vectors and @code{@var{z}} is matrix.
aa40bdbfa478 griddata.m: Allow x, y inputs to be vectors, and z a matrix. Ben Abbott <bpabbott@mac.com> parents: 10793 diff changeset	27 ##
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	28 ## The interpolation points are all @code{(@var{xi}, @var{yi})}. If
11563 3c6e8aaa9555 Grammarcheck m-files before 3.4 release. Rik <octave@nomad.inbox5.com> parents: 11523 diff changeset	29 ## @var{xi}, @var{yi} are vectors then they are made into a 2-D mesh.
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	30 ##
6826 8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	31 ## The interpolation method can be @code{"nearest"}, @code{"cubic"} or
8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	32 ## @code{"linear"}. If method is omitted it defaults to @code{"linear"}.
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	33 ## @seealso{delaunay}
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	34 ## @end deftypefn
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	35
10549 95c3e38098bf Untabify .m scripts Rik <code@nomad.inbox5.com> parents: 10548 diff changeset	36 ## Author: Kai Habel <kai.habel@gmx.de>
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	37 ## Adapted-by: Alexander Barth <barth.alexander@gmail.com>
10945 aa40bdbfa478 griddata.m: Allow x, y inputs to be vectors, and z a matrix. Ben Abbott <bpabbott@mac.com> parents: 10793 diff changeset	38 ## xi and yi are not "meshgridded" if both are vectors
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	39 ## of the same size (for compatibility)
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	40
6826 8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	41 function [rx, ry, rz] = griddata (x, y, z, xi, yi, method)
10945 aa40bdbfa478 griddata.m: Allow x, y inputs to be vectors, and z a matrix. Ben Abbott <bpabbott@mac.com> parents: 10793 diff changeset	42
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	43 if (nargin == 5)
6826 8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	44 method = "linear";
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	45 endif
10945 aa40bdbfa478 griddata.m: Allow x, y inputs to be vectors, and z a matrix. Ben Abbott <bpabbott@mac.com> parents: 10793 diff changeset	46 if (nargin < 5 \|\| nargin > 7)
6826 8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	47 print_usage ();
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	48 endif
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	49
6826 8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	50 if (ischar (method))
8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	51 method = tolower (method);
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	52 endif
10945 aa40bdbfa478 griddata.m: Allow x, y inputs to be vectors, and z a matrix. Ben Abbott <bpabbott@mac.com> parents: 10793 diff changeset	53
aa40bdbfa478 griddata.m: Allow x, y inputs to be vectors, and z a matrix. Ben Abbott <bpabbott@mac.com> parents: 10793 diff changeset	54 if (isvector (x) && isvector (y) && all ([numel(y), numel(x)] == size (z)))
aa40bdbfa478 griddata.m: Allow x, y inputs to be vectors, and z a matrix. Ben Abbott <bpabbott@mac.com> parents: 10793 diff changeset	55 [x, y] = meshgrid (x, y);
aa40bdbfa478 griddata.m: Allow x, y inputs to be vectors, and z a matrix. Ben Abbott <bpabbott@mac.com> parents: 10793 diff changeset	56 elseif (! all (size (x) == size (y) & size (x) == size (z)))
aa40bdbfa478 griddata.m: Allow x, y inputs to be vectors, and z a matrix. Ben Abbott <bpabbott@mac.com> parents: 10793 diff changeset	57 if (isvector (z))
11588 d5bd2766c640 style fixes for warning and error messages in script files John W. Eaton <jwe@octave.org> parents: 11563 diff changeset	58 error ("griddata: X, Y, and Z, be vectors of same length");
10945 aa40bdbfa478 griddata.m: Allow x, y inputs to be vectors, and z a matrix. Ben Abbott <bpabbott@mac.com> parents: 10793 diff changeset	59 else
11588 d5bd2766c640 style fixes for warning and error messages in script files John W. Eaton <jwe@octave.org> parents: 11563 diff changeset	60 error ("griddata: lengths of X, Y must match the columns and rows of Z");
10945 aa40bdbfa478 griddata.m: Allow x, y inputs to be vectors, and z a matrix. Ben Abbott <bpabbott@mac.com> parents: 10793 diff changeset	61 endif
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	62 endif
10945 aa40bdbfa478 griddata.m: Allow x, y inputs to be vectors, and z a matrix. Ben Abbott <bpabbott@mac.com> parents: 10793 diff changeset	63
9677 8cf522ce9c4d fix griddata with vectors Jaroslav Hajek <highegg@gmail.com> parents: 9501 diff changeset	64 ## Meshgrid xi and yi if they are a row and column vector.
8cf522ce9c4d fix griddata with vectors Jaroslav Hajek <highegg@gmail.com> parents: 9501 diff changeset	65 if (rows (xi) == 1 && columns (yi) == 1)
6826 8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	66 [xi, yi] = meshgrid (xi, yi);
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	67 endif
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	68
9677 8cf522ce9c4d fix griddata with vectors Jaroslav Hajek <highegg@gmail.com> parents: 9501 diff changeset	69 if (! size_equal (xi, yi))
11472 1740012184f9 Use uppercase for variable names in error() strings to match Info documentation. Only m-files done. Rik <octave@nomad.inbox5.com> parents: 10945 diff changeset	70 error ("griddata: XI and YI must be vectors or matrices of same size");
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	71 endif
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	72
6826 8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	73 [nr, nc] = size (xi);
10945 aa40bdbfa478 griddata.m: Allow x, y inputs to be vectors, and z a matrix. Ben Abbott <bpabbott@mac.com> parents: 10793 diff changeset	74
9501 3c40d81c197f ChangeLog and style fixes John W. Eaton <jwe@octave.org> parents: 9496 diff changeset	75 x = x(:);
3c40d81c197f ChangeLog and style fixes John W. Eaton <jwe@octave.org> parents: 9496 diff changeset	76 y = y(:);
3c40d81c197f ChangeLog and style fixes John W. Eaton <jwe@octave.org> parents: 9496 diff changeset	77 z = z(:);
9495 0a427d3244bf fix griddata Olaf Till <olaf.till@uni-jena.de> parents: 8920 diff changeset	78
8507 cadc73247d65 style fixes John W. Eaton <jwe@octave.org> parents: 8153 diff changeset	79 ## Triangulate data.
6826 8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	80 tri = delaunay (x, y);
10548 479536c5bb10 Replace lowercase nan with NaN for visual cue in scripts Rik <code@nomad.inbox5.com> parents: 9677 diff changeset	81 zi = NaN (size (xi));
10945 aa40bdbfa478 griddata.m: Allow x, y inputs to be vectors, and z a matrix. Ben Abbott <bpabbott@mac.com> parents: 10793 diff changeset	82
6826 8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	83 if (strcmp (method, "cubic"))
8664 e07e93c04080 style fixes John W. Eaton <jwe@octave.org> parents: 8507 diff changeset	84 error ("griddata: cubic interpolation not yet implemented");
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	85
6826 8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	86 elseif (strcmp (method, "nearest"))
8507 cadc73247d65 style fixes John W. Eaton <jwe@octave.org> parents: 8153 diff changeset	87 ## Search index of nearest point.
6826 8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	88 idx = dsearch (x, y, tri, xi, yi);
8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	89 valid = !isnan (idx);
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	90 zi(valid) = z(idx(valid));
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	91
6826 8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	92 elseif (strcmp (method, "linear"))
8507 cadc73247d65 style fixes John W. Eaton <jwe@octave.org> parents: 8153 diff changeset	93 ## Search for every point the enclosing triangle.
cadc73247d65 style fixes John W. Eaton <jwe@octave.org> parents: 8153 diff changeset	94 tri_list = tsearch (x, y, tri, xi(:), yi(:));
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	95
8507 cadc73247d65 style fixes John W. Eaton <jwe@octave.org> parents: 8153 diff changeset	96 ## Only keep the points within triangles.
9496 079c06f37f17 optimize griddata Jaroslav Hajek <highegg@gmail.com> parents: 9495 diff changeset	97 valid = !isnan (tri_list);
079c06f37f17 optimize griddata Jaroslav Hajek <highegg@gmail.com> parents: 9495 diff changeset	98 tri_list = tri_list(valid);
6826 8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	99 nr_t = rows (tri_list);
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	100
9496 079c06f37f17 optimize griddata Jaroslav Hajek <highegg@gmail.com> parents: 9495 diff changeset	101 tri = tri(tri_list,:);
079c06f37f17 optimize griddata Jaroslav Hajek <highegg@gmail.com> parents: 9495 diff changeset	102
8507 cadc73247d65 style fixes John W. Eaton <jwe@octave.org> parents: 8153 diff changeset	103 ## Assign x,y,z for each point of triangle.
9496 079c06f37f17 optimize griddata Jaroslav Hajek <highegg@gmail.com> parents: 9495 diff changeset	104 x1 = x(tri(:,1));
079c06f37f17 optimize griddata Jaroslav Hajek <highegg@gmail.com> parents: 9495 diff changeset	105 x2 = x(tri(:,2));
079c06f37f17 optimize griddata Jaroslav Hajek <highegg@gmail.com> parents: 9495 diff changeset	106 x3 = x(tri(:,3));
6826 8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	107
9496 079c06f37f17 optimize griddata Jaroslav Hajek <highegg@gmail.com> parents: 9495 diff changeset	108 y1 = y(tri(:,1));
079c06f37f17 optimize griddata Jaroslav Hajek <highegg@gmail.com> parents: 9495 diff changeset	109 y2 = y(tri(:,2));
079c06f37f17 optimize griddata Jaroslav Hajek <highegg@gmail.com> parents: 9495 diff changeset	110 y3 = y(tri(:,3));
6826 8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	111
9496 079c06f37f17 optimize griddata Jaroslav Hajek <highegg@gmail.com> parents: 9495 diff changeset	112 z1 = z(tri(:,1));
079c06f37f17 optimize griddata Jaroslav Hajek <highegg@gmail.com> parents: 9495 diff changeset	113 z2 = z(tri(:,2));
079c06f37f17 optimize griddata Jaroslav Hajek <highegg@gmail.com> parents: 9495 diff changeset	114 z3 = z(tri(:,3));
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	115
8507 cadc73247d65 style fixes John W. Eaton <jwe@octave.org> parents: 8153 diff changeset	116 ## Calculate norm vector.
6826 8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	117 N = cross ([x2-x1, y2-y1, z2-z1], [x3-x1, y3-y1, z3-z1]);
9496 079c06f37f17 optimize griddata Jaroslav Hajek <highegg@gmail.com> parents: 9495 diff changeset	118 ## Normalize.
079c06f37f17 optimize griddata Jaroslav Hajek <highegg@gmail.com> parents: 9495 diff changeset	119 N = diag (norm (N, "rows")) \ N;
10945 aa40bdbfa478 griddata.m: Allow x, y inputs to be vectors, and z a matrix. Ben Abbott <bpabbott@mac.com> parents: 10793 diff changeset	120
8507 cadc73247d65 style fixes John W. Eaton <jwe@octave.org> parents: 8153 diff changeset	121 ## Calculate D of plane equation
cadc73247d65 style fixes John W. Eaton <jwe@octave.org> parents: 8153 diff changeset	122 ## Ax+By+Cz+D = 0;
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	123 D = -(N(:,1) .* x1 + N(:,2) .* y1 + N(:,3) .* z1);
10945 aa40bdbfa478 griddata.m: Allow x, y inputs to be vectors, and z a matrix. Ben Abbott <bpabbott@mac.com> parents: 10793 diff changeset	124
8507 cadc73247d65 style fixes John W. Eaton <jwe@octave.org> parents: 8153 diff changeset	125 ## Calculate zi by solving plane equation for xi, yi.
9677 8cf522ce9c4d fix griddata with vectors Jaroslav Hajek <highegg@gmail.com> parents: 9501 diff changeset	126 zi(valid) = -(N(:,1).xi(:)(valid) + N(:,2).yi(:)(valid) + D) ./ N(:,3);
10945 aa40bdbfa478 griddata.m: Allow x, y inputs to be vectors, and z a matrix. Ben Abbott <bpabbott@mac.com> parents: 10793 diff changeset	127
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	128 else
11472 1740012184f9 Use uppercase for variable names in error() strings to match Info documentation. Only m-files done. Rik <octave@nomad.inbox5.com> parents: 10945 diff changeset	129 error ("griddata: unknown interpolation METHOD");
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	130 endif
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	131
6826 8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	132 if (nargout == 3)
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	133 rx = xi;
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	134 ry = yi;
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	135 rz = zi;
6826 8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	136 elseif (nargout == 1)
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	137 rx = zi;
6826 8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	138 elseif (nargout == 0)
8618f29520c6 [project @ 2007-08-24 16:02:07 by jwe] jwe parents: 6823 diff changeset	139 mesh (xi, yi, zi);
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	140 endif
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	141 endfunction
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	142
8153 ec0a13863eb7 Only run tests that depend on HDF5 and QHull if Octave was actually Soren Hauberg <hauberg@gmail.com> parents: 7017 diff changeset	143 %!testif HAVE_QHULL
6823 9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	144 %! [xx,yy]=meshgrid(linspace(-1,1,32));
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	145 %! x = xx(:);
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	146 %! x = x + 10 * (2 * round(rand(size(x))) - 1) * eps;
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	147 %! y = yy(:);
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	148 %! y = y + 10 * (2 * round(rand(size(y))) - 1) * eps;
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	149 %! z = sin(2*(x.^2+y.^2));
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	150 %! zz = griddata(x,y,z,xx,yy,'linear');
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	151 %! zz2 = sin(2*(xx.^2+yy.^2));
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	152 %! zz2(isnan(zz)) = NaN;
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	153 %! assert (zz, zz2, 100 * eps)
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	154
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	155 %!demo
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	156 %! x=2*rand(100,1)-1;
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	157 %! y=2*rand(size(x))-1;
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	158 %! z=sin(2*(x.^2+y.^2));
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	159 %! [xx,yy]=meshgrid(linspace(-1,1,32));
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	160 %! griddata(x,y,z,xx,yy);
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	161 %! title('nonuniform grid sampled at 100 points');
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	162
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	163 %!demo
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	164 %! x=2*rand(1000,1)-1;
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	165 %! y=2*rand(size(x))-1;
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	166 %! z=sin(2*(x.^2+y.^2));
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	167 %! [xx,yy]=meshgrid(linspace(-1,1,32));
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	168 %! griddata(x,y,z,xx,yy);
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	169 %! title('nonuniform grid sampled at 1000 points');
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	170
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	171 %!demo
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	172 %! x=2*rand(1000,1)-1;
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	173 %! y=2*rand(size(x))-1;
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	174 %! z=sin(2*(x.^2+y.^2));
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	175 %! [xx,yy]=meshgrid(linspace(-1,1,32));
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	176 %! griddata(x,y,z,xx,yy,'nearest');
9fddcc586065 [project @ 2007-08-24 08:27:27 by dbateman] dbateman parents: diff changeset	177 %! title('nonuniform grid sampled at 1000 points with nearest neighbor');

Mercurial > octave

annotate scripts/geometry/griddata.m @ 14138:72c96de7a403 stable