Mercurial > octave
view scripts/general/divergence.m @ 27978:a4268efb7334
maint: Eliminate single "Author:" lines from code base.
* color-picker.cc, color-picker.h, octave-qscintilla.cc, octave-qscintilla.h,
octave-txt-lexer.cc, octave-txt-lexer.h, balance.cc, kron.cc, lookup.cc,
ls-hdf5.cc, ls-mat5.cc, ls-oct-text.cc, sylvester.cc, tsearch.cc, jit-ir.cc,
jit-ir.h, jit-typeinfo.cc, jit-typeinfo.h, jit-util.cc, jit-util.h, pt-jit.cc,
pt-jit.h, Array-jit.cc, bsxfun.h, url-transfer.cc, url-transfer.h, acosd.m,
acotd.m, acscd.m, asecd.m, asind.m, atand.m, cosd.m, cotd.m, cscd.m, secd.m,
sind.m, tand.m, cart2pol.m, cart2sph.m, curl.m, del2.m, divergence.m, flip.m,
pol2cart.m, randi.m, sortrows.m, sph2cart.m, griddata3.m, griddatan.m,
rectint.m, voronoi.m, dialog.m, guidata.m, guihandles.m, __file_filter__.m,
__fltk_file_filter__.m, __get_funcname__.m, __is_function__.m,
__uigetdir_fltk__.m, __uigetfile_fltk__.m, __uiobject_split_args__.m,
__uiputfile_fltk__.m, uibuttongroup.m, uicontextmenu.m, uicontrol.m,
uigetdir.m, uigetfile.m, uimenu.m, uipanel.m, uipushtool.m, uiputfile.m,
uiresume.m, uitoggletool.m, uitoolbar.m, uiwait.m, doc.m, autumn.m, bone.m,
cmpermute.m, cmunique.m, cool.m, copper.m, cubehelix.m, flag.m, frame2im.m,
hot.m, hsv.m, hsv2rgb.m, im2frame.m, imfinfo.m, imformats.m, iscolormap.m,
jet.m, pink.m, prism.m, __imfinfo__.m, rainbow.m, rgb2hsv.m, spinmap.m,
spring.m, viridis.m, white.m, winter.m, importdata.m, strmatch.m, bandwidth.m,
isbanded.m, isdiag.m, istril.m, istriu.m, krylov.m, linsolve.m, logm.m,
lscov.m, subspace.m, bunzip2.m, compare_versions.m, edit.m, fullfile.m,
getfield.m, gunzip.m, inputParser.m, license.m, nargchk.m, narginchk.m,
nthargout.m, python.m, setfield.m, tar.m, unpack.m, ver.m, zip.m, odeplot.m,
fminbnd.m, fminunc.m, fsolve.m, fzero.m, glpk.m, humps.m, pathdef.m,
savepath.m, diffuse.m, lighting.m, material.m, shading.m, specular.m,
contour.m, ellipsoid.m, isocaps.m, isocolors.m, isonormals.m, isosurface.m,
light.m, pcolor.m, __interp_cube__.m, __marching_cube__.m, __patch__.m,
__stem__.m, reducepatch.m, reducevolume.m, ribbon.m, shrinkfaces.m, slice.m,
stem.m, surf.m, surfl.m, tetramesh.m, waterfall.m, __actual_axis_position__.m,
__next_line_color__.m, allchild.m, figure.m, findall.m, findobj.m, gcf.m,
hggroup.m, isprop.m, ndgrid.m, __add_default_menu__.m, saveas.m,
__splinefit__.m, prefdir.m, preferences.m, profexplore.m, profexport.m,
profile.m, profshow.m, setdiff.m, freqz.m, freqz_plot.m, sinc.m, unwrap.m,
pcr.m, qmr.m, sprandn.m, betaincinv.m, cosint.m, ellipke.m, factor.m,
gammaincinv.m, legendre.m, nchoosek.m, primes.m, invhilb.m, toeplitz.m,
erase.m, mat2str.m, strtrim.m, validatestring.m, fail.m, compare_plot_demos.m,
dump_demos.m, html_compare_plot_demos.m, addtodate.m, datenum.m, jit.tst:
Eliminate single "Author:" lines from code base.
author | Rik <rik@octave.org> |
---|---|
date | Tue, 21 Jan 2020 12:53:13 -0800 |
parents | bd51beb6205e |
children | 0a5b15007766 |
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######################################################################## ## ## Copyright (C) 2009-2020 The Octave Project Developers ## ## See the file COPYRIGHT.md in the top-level directory of this ## distribution or <https://octave.org/copyright/>. ## ## This file is part of Octave. ## ## Octave is free software: you can redistribute it and/or modify it ## under the terms of the GNU General Public License as published by ## the Free Software Foundation, either version 3 of the License, or ## (at your option) any later version. ## ## Octave is distributed in the hope that it will be useful, but ## WITHOUT ANY WARRANTY; without even the implied warranty of ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ## GNU General Public License for more details. ## ## You should have received a copy of the GNU General Public License ## along with Octave; see the file COPYING. If not, see ## <https://www.gnu.org/licenses/>. ## ######################################################################## ## -*- texinfo -*- ## @deftypefn {} {@var{div} =} divergence (@var{x}, @var{y}, @var{z}, @var{fx}, @var{fy}, @var{fz}) ## @deftypefnx {} {@var{div} =} divergence (@var{fx}, @var{fy}, @var{fz}) ## @deftypefnx {} {@var{div} =} divergence (@var{x}, @var{y}, @var{fx}, @var{fy}) ## @deftypefnx {} {@var{div} =} divergence (@var{fx}, @var{fy}) ## Calculate divergence of a vector field given by the arrays @var{fx}, ## @var{fy}, and @var{fz} or @var{fx}, @var{fy} respectively. ## ## @tex ## $$ ## div F(x,y,z) = \partial_x{F} + \partial_y{F} + \partial_z{F} ## $$ ## @end tex ## @ifnottex ## ## @example ## @group ## d d d ## div F(x,y,z) = -- F(x,y,z) + -- F(x,y,z) + -- F(x,y,z) ## dx dy dz ## @end group ## @end example ## ## @end ifnottex ## The coordinates of the vector field can be given by the arguments @var{x}, ## @var{y}, @var{z} or @var{x}, @var{y} respectively. ## ## @seealso{curl, gradient, del2, dot} ## @end deftypefn function retval = divergence (varargin) fidx = 1; if (nargin == 2) sz = size (varargin{fidx}); dx = (1:sz(2))(:); dy = (1:sz(1))(:); elseif (nargin == 3) sz = size (varargin{fidx}); dx = 1:sz(2); dy = 1:sz(1); dz = 1:sz(3); elseif (nargin == 4) fidx = 3; dx = varargin{1}(1,:); dy = varargin{2}(:,1); elseif (nargin == 6) fidx = 4; dx = varargin{1}(1,:,1)(:); dy = varargin{2}(:,1,1)(:); dz = varargin{3}(1,1,:)(:); else print_usage (); endif if (nargin == 4 || nargin == 2) if (! size_equal (varargin{fidx},varargin{fidx + 1})) error ("divergence: size of X and Y must match"); elseif (ndims (varargin{fidx}) != 2) error ("divergence: X and Y must be 2-D matrices"); elseif (length (dx) != columns (varargin{fidx}) || length (dy) != rows (varargin{fidx})) error ("divergence: size of dx and dy must match the respective dimension of X and Y"); endif retval = gradient (varargin{fidx}, dx, dy); retval += gradient (varargin{fidx + 1}.', dy, dx).'; elseif (nargin == 6 || nargin == 3) if (! size_equal (varargin{fidx},varargin{fidx + 1},varargin{fidx + 2})) error ("divergence: size of X, Y, and Z must match"); elseif (ndims (varargin{fidx}) != 3) error ("divergence: X, Y, and Z must be 2-D matrices"); elseif ((length (dx) != size (varargin{fidx}, 2)) || (length (dy) != size (varargin{fidx}, 1)) || (length (dz) != size (varargin{fidx}, 3))) error ("divergence: size of dx, dy, and dz must match the respective dimesion of X, Y, and Z"); endif ## x-direction retval = gradient (varargin{fidx}, dx, dy, dz); ## y-direction retval += shiftdim (gradient (shiftdim (varargin{fidx + 1}, 2), dy), 1); ## z-direction retval += shiftdim (gradient (shiftdim (varargin{fidx + 2}, 1), dz), 2); endif endfunction %!test %! [X,Y] = meshgrid (-20:20,-22:22); %! div = divergence (X-Y,Y); %! assert (all (div(:) == 2)); %! assert (size_equal (X,Y,div));