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Use Octave syntax in graphics demos.
* inputdlg.m, listdlg.m, waitbar.m, autumn.m, bone.m, cool.m, copper.m,
cubehelix.m, flag.m, gray.m, hot.m, hsv.m, jet.m, lines.m, ocean.m, pink.m,
prism.m, rainbow.m, rgbplot.m, spring.m, summer.m, viridis.m, white.m,
winter.m, annotation.m, axis.m, clabel.m, daspect.m, datetick.m, grid.m,
legend.m, lighting.m, material.m, pbaspect.m, shading.m, text.m, xlim.m,
ylim.m, zlim.m, area.m, bar.m, barh.m, camlight.m, colorbar.m, comet.m,
comet3.m, contour.m, contour3.m, contourf.m, cylinder.m, ellipsoid.m,
errorbar.m, ezcontour.m, ezcontourf.m, ezmesh.m, ezmeshc.m, ezplot.m,
ezplot3.m, ezsurf.m, ezsurfc.m, feather.m, fill.m, fplot.m, isocaps.m,
isonormals.m, isosurface.m, light.m, line.m, loglog.m, loglogerr.m, mesh.m,
meshc.m, meshz.m, pareto.m, patch.m, pcolor.m, pie.m, pie3.m, plot.m, plot3.m,
plotmatrix.m, plotyy.m, polar.m, quiver.m, quiver3.m, rectangle.m, ribbon.m,
rose.m, scatter.m, scatter3.m, semilogx.m, semilogxerr.m, semilogy.m,
semilogyerr.m, shrinkfaces.m, slice.m, smooth3.m, sombrero.m, stairs.m, stem.m,
stem3.m, stemleaf.m, surf.m, surfc.m, surfl.m, surfnorm.m, tetramesh.m,
trimesh.m, triplot.m, trisurf.m, waterfall.m, copyobj.m, hold.m, linkaxes.m,
linkprop.m, printd.m, refreshdata.m, subplot.m, zoom.m, pcr.m, dump_demos.m:
Use Octave syntax in graphics demos.
author | Rik <rik@octave.org> |
---|---|
date | Mon, 15 Aug 2016 15:15:30 -0700 |
parents | 516bb87ea72e |
children | 533c3c4059a3 |
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## Copyright (C) 2007-2015 David Bateman ## ## 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 ## <http://www.gnu.org/licenses/>. ## -*- texinfo -*- ## @deftypefn {} {} surfnorm (@var{x}, @var{y}, @var{z}) ## @deftypefnx {} {} surfnorm (@var{z}) ## @deftypefnx {} {} surfnorm (@dots{}, @var{prop}, @var{val}, @dots{}) ## @deftypefnx {} {} surfnorm (@var{hax}, @dots{}) ## @deftypefnx {} {[@var{nx}, @var{ny}, @var{nz}] =} surfnorm (@dots{}) ## Find the vectors normal to a meshgridded surface. ## ## If @var{x} and @var{y} are vectors, then a typical vertex is ## (@var{x}(j), @var{y}(i), @var{z}(i,j)). Thus, columns of @var{z} correspond ## to different @var{x} values and rows of @var{z} correspond to different ## @var{y} values. If only a single input @var{z} is given then @var{x} is ## taken to be @code{1:rows (@var{z})} and @var{y} is ## @code{1:columns (@var{z})}. ## ## If no return arguments are requested, a surface plot with the normal ## vectors to the surface is plotted. ## ## Any property/value input pairs are assigned to the surface object. ## ## If the first argument @var{hax} is an axes handle, then plot into this axis, ## rather than the current axes returned by @code{gca}. ## ## If output arguments are requested then the components of the normal ## vectors are returned in @var{nx}, @var{ny}, and @var{nz} and no plot is ## made. The normal vectors are unnormalized (magnitude != 1). To normalize, ## use ## ## @example ## @group ## mag = sqrt (nx.^2 + ny.^2 + nz.^2); ## nx ./= len; ny ./= len; nz ./= len; ## @end group ## @end example ## ## An example of the use of @code{surfnorm} is ## ## @example ## surfnorm (peaks (25)); ## @end example ## ## Algorithm: The normal vectors are calculated by taking the cross product ## of the diagonals of each of the quadrilateral faces in the meshgrid to find ## the normal vectors at the center of each face. Next, for each meshgrid ## point the four nearest normal vectors are averaged to obtain the final ## normal to the surface at the meshgrid point. ## ## For surface objects, the @qcode{"VertexNormals"} property contains ## equivalent information, except possibly near the boundary of the surface ## where different interpolation schemes may yield slightly different values. ## ## @seealso{isonormals, quiver3, surf, meshgrid} ## @end deftypefn function [Nx, Ny, Nz] = surfnorm (varargin) [hax, varargin, nargin] = __plt_get_axis_arg__ ("surfnorm", varargin{:}); if (nargin == 0 || nargin == 2) print_usage (); endif if (nargin == 1) z = varargin{1}; [x, y] = meshgrid (1:columns (z), 1:rows (z)); ioff = 2; else x = varargin{1}; y = varargin{2}; z = varargin{3}; ioff = 4; endif if (iscomplex (z) || iscomplex (x) || iscomplex (y)) error ("surfnorm: X, Y, and Z must be 2-D real matrices"); endif if (! size_equal (x, y, z)) error ("surfnorm: X, Y, and Z must have the same dimensions"); endif ## FIXME: Matlab uses a bicubic interpolation, not linear, along the boundary. ## Do a linear extrapolation for mesh points on the boundary so that the mesh ## is increased by 1 on each side. This allows each original meshgrid point ## to be surrounded by four quadrilaterals and the same calculation can be ## used for interior and boundary points. The extrapolation works badly for ## closed surfaces like spheres. xx = [2 * x(:,1) - x(:,2), x, 2 * x(:,end) - x(:,end-1)]; xx = [2 * xx(1,:) - xx(2,:); xx; 2 * xx(end,:) - xx(end-1,:)]; yy = [2 * y(:,1) - y(:,2), y, 2 * y(:,end) - y(:,end-1)]; yy = [2 * yy(1,:) - yy(2,:); yy; 2 * yy(end,:) - yy(end-1,:)]; zz = [2 * z(:,1) - z(:,2), z, 2 * z(:,end) - z(:,end-1)]; zz = [2 * zz(1,:) - zz(2,:); zz; 2 * zz(end,:) - zz(end-1,:)]; u.x = xx(1:end-1,1:end-1) - xx(2:end,2:end); u.y = yy(1:end-1,1:end-1) - yy(2:end,2:end); u.z = zz(1:end-1,1:end-1) - zz(2:end,2:end); v.x = xx(1:end-1,2:end) - xx(2:end,1:end-1); v.y = yy(1:end-1,2:end) - yy(2:end,1:end-1); v.z = zz(1:end-1,2:end) - zz(2:end,1:end-1); c = cross ([u.x(:), u.y(:), u.z(:)], [v.x(:), v.y(:), v.z(:)]); w.x = reshape (c(:,1), size (u.x)); w.y = reshape (c(:,2), size (u.y)); w.z = reshape (c(:,3), size (u.z)); ## Create normal vectors as mesh vectices from normals at mesh centers nx = (w.x(1:end-1,1:end-1) + w.x(1:end-1,2:end) + w.x(2:end,1:end-1) + w.x(2:end,2:end)) / 4; ny = (w.y(1:end-1,1:end-1) + w.y(1:end-1,2:end) + w.y(2:end,1:end-1) + w.y(2:end,2:end)) / 4; nz = (w.z(1:end-1,1:end-1) + w.z(1:end-1,2:end) + w.z(2:end,1:end-1) + w.z(2:end,2:end)) / 4; if (nargout == 0) oldfig = []; if (! isempty (hax)) oldfig = get (0, "currentfigure"); endif unwind_protect hax = newplot (hax); surf (x, y, z, varargin{ioff:end}); old_hold_state = get (hax, "nextplot"); unwind_protect set (hax, "nextplot", "add"); ## Normalize the normal vectors nmag = sqrt (nx.^2 + ny.^2 + nz.^2); ## And correct for the aspect ratio of the display daratio = daspect (hax); damag = sqrt (sumsq (daratio)); ## FIXME: May also want to normalize the vectors relative to the size ## of the diagonal. nx ./= nmag / (daratio(1)^2 / damag); ny ./= nmag / (daratio(2)^2 / damag); nz ./= nmag / (daratio(3)^2 / damag); plot3 ([x(:).'; x(:).' + nx(:).' ; NaN(size(x(:).'))](:), [y(:).'; y(:).' + ny(:).' ; NaN(size(y(:).'))](:), [z(:).'; z(:).' + nz(:).' ; NaN(size(z(:).'))](:), "r"); unwind_protect_cleanup set (hax, "nextplot", old_hold_state); end_unwind_protect unwind_protect_cleanup if (! isempty (oldfig)) set (0, "currentfigure", oldfig); endif end_unwind_protect else Nx = nx; Ny = ny; Nz = nz; endif endfunction %!demo %! clf; %! colormap ("default"); %! surfnorm (peaks (19)); %! shading faceted; %! title ({"surfnorm() shows surface and normals at each vertex", ... %! "peaks() function with 19 faces"}); %!demo %! clf; %! colormap ("default"); %! [x, y, z] = sombrero (10); %! surfnorm (x, y, z); ## Test input validation %!error surfnorm () %!error surfnorm (1,2) %!error <X, Y, and Z must be 2-D real matrices> surfnorm (i) %!error <X, Y, and Z must be 2-D real matrices> surfnorm (i, 1, 1) %!error <X, Y, and Z must be 2-D real matrices> surfnorm (1, i, 1) %!error <X, Y, and Z must be 2-D real matrices> surfnorm (1, 1, i) %!error <X, Y, and Z must have the same dimensions> surfnorm ([1 2], 1, 1) %!error <X, Y, and Z must have the same dimensions> surfnorm (1, [1 2], 1) %!error <X, Y, and Z must have the same dimensions> surfnorm (1, 1, [1 2])