Mercurial > octave-antonio
view scripts/plot/contourc.m @ 17122:eaab03308c0b
doc: Rewrite docstrings for most plot functions.
Emphasize clarity, use common "voice", and increase density of seealso links.
* doc/interpreter/plot.txi: Add @findex entries that were in xlim.m
* scripts/miscellaneous/getappdata.m scripts/miscellaneous/setappdata.m,
scripts/plot/allchild.m, scripts/plot/ancestor.m, scripts/plot/area.m,
scripts/plot/axes.m, scripts/plot/axis.m, scripts/plot/bar.m,
scripts/plot/barh.m, scripts/plot/box.m, scripts/plot/caxis.m,
scripts/plot/cla.m, scripts/plot/clabel.m, scripts/plot/clf.m,
scripts/plot/close.m, scripts/plot/closereq.m, scripts/plot/colorbar.m,
scripts/plot/comet.m, scripts/plot/comet3.m, scripts/plot/compass.m,
scripts/plot/contour.m, scripts/plot/contour3.m, scripts/plot/contourc.m,
scripts/plot/contourf.m, scripts/plot/copyobj.m, scripts/plot/cylinder.m,
scripts/plot/daspect.m, scripts/plot/diffuse.m, scripts/plot/ellipsoid.m,
scripts/plot/errorbar.m, scripts/plot/ezcontour.m, scripts/plot/ezcontourf.m,
scripts/plot/ezmesh.m, scripts/plot/ezmeshc.m, scripts/plot/ezplot.m,
scripts/plot/ezplot3.m, scripts/plot/ezpolar.m, scripts/plot/ezsurf.m,
scripts/plot/ezsurfc.m, scripts/plot/feather.m, scripts/plot/figure.m,
scripts/plot/fill.m, scripts/plot/findall.m, scripts/plot/findobj.m,
scripts/plot/fplot.m, scripts/plot/gca.m, scripts/plot/gcbf.m,
scripts/plot/gcbo.m, scripts/plot/gcf.m, scripts/plot/gco.m,
scripts/plot/ginput.m, scripts/plot/graphics_toolkit.m, scripts/plot/grid.m,
scripts/plot/gtext.m, scripts/plot/guidata.m, scripts/plot/guihandles.m,
scripts/plot/hdl2struct.m, scripts/plot/hggroup.m, scripts/plot/hidden.m,
scripts/plot/hist.m, scripts/plot/hold.m, scripts/plot/ishghandle.m,
scripts/plot/ishold.m, scripts/plot/isocolors.m, scripts/plot/isprop.m,
scripts/plot/legend.m, scripts/plot/line.m, scripts/plot/linkprop.m,
scripts/plot/loglog.m, scripts/plot/loglogerr.m, scripts/plot/mesh.m,
scripts/plot/meshc.m, scripts/plot/meshgrid.m, scripts/plot/meshz.m,
scripts/plot/newplot.m, scripts/plot/orient.m, scripts/plot/pareto.m,
scripts/plot/patch.m, scripts/plot/pcolor.m, scripts/plot/peaks.m,
scripts/plot/pie.m, scripts/plot/pie3.m, scripts/plot/plot.m,
scripts/plot/plot3.m, scripts/plot/plotmatrix.m, scripts/plot/plotyy.m,
scripts/plot/polar.m, scripts/plot/print.m, scripts/plot/quiver.m,
scripts/plot/quiver3.m, scripts/plot/rectangle.m, scripts/plot/refresh.m,
scripts/plot/refreshdata.m, scripts/plot/ribbon.m, scripts/plot/rose.m,
scripts/plot/saveas.m, scripts/plot/scatter.m, scripts/plot/scatter3.m,
scripts/plot/semilogx.m, scripts/plot/semilogxerr.m, scripts/plot/semilogy.m,
scripts/plot/semilogyerr.m, scripts/plot/shading.m, scripts/plot/shg.m,
scripts/plot/shrinkfaces.m, scripts/plot/slice.m, scripts/plot/specular.m,
scripts/plot/sphere.m, scripts/plot/stairs.m, scripts/plot/stem.m,
scripts/plot/stem3.m, scripts/plot/struct2hdl.m, scripts/plot/subplot.m,
scripts/plot/surf.m, scripts/plot/surface.m, scripts/plot/surfc.m,
scripts/plot/surfl.m, scripts/plot/tetramesh.m, scripts/plot/text.m,
scripts/plot/title.m, scripts/plot/trimesh.m, scripts/plot/triplot.m,
scripts/plot/trisurf.m, scripts/plot/view.m, scripts/plot/waitbar.m,
scripts/plot/waitforbuttonpress.m, scripts/plot/waterfall.m,
scripts/plot/whitebg.m, scripts/plot/xlabel.m, scripts/plot/xlim.m,
scripts/plot/ylabel.m, scripts/plot/ylim.m, scripts/plot/zlabel.m,
scripts/plot/zlim.m: Rewrite docstrings for most plot functions.
Emphasize clarity, use common "voice", and increase density of seealso links.
author | Rik <rik@octave.org> |
---|---|
date | Wed, 31 Jul 2013 13:53:30 -0700 |
parents | 64e7bb01fce2 |
children | 56e72e8d1aba |
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## Copyright (C) 2003-2012 Shai Ayal ## ## 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 {Function File} {[@var{c}, @var{lev}] =} contourc (@var{z}) ## @deftypefnx {Function File} {[@var{c}, @var{lev}] =} contourc (@var{z}, @var{vn}) ## @deftypefnx {Function File} {[@var{c}, @var{lev}] =} contourc (@var{x}, @var{y}, @var{z}) ## @deftypefnx {Function File} {[@var{c}, @var{lev}] =} contourc (@var{x}, @var{y}, @var{z}, @var{vn}) ## Compute contour lines (isolines of constant Z value). ## ## The matrix @var{z} contains height values above the rectangular grid ## determined by @var{x} and @var{y}. If only a single input @var{z} is ## provided then @var{x} is taken to be @code{1:rows (@var{z})} and @var{y} is ## taken to be @code{1:columns (@var{z})}. ## ## The optional input @var{vn} is either a scalar denoting the number of ## contour lines to compute or a vector containing the Z values where lines ## will be computed. When @var{vn} is a vector the number of contour lines ## is @code{numel (@var{vn})}. However, to compute a single contour line ## at a given value use @code{@var{vn} = [val, val]}. If @var{vn} is omitted ## it defaults to 10. ## ## The return value @var{c} is a 2x@var{n} matrix containing the ## contour lines in the following format ## ## @example ## @group ## @var{c} = [lev1, x1, x2, @dots{}, levn, x1, x2, ... ## len1, y1, y2, @dots{}, lenn, y1, y2, @dots{}] ## @end group ## @end example ## ## @noindent ## in which contour line @var{n} has a level (height) of @var{levn} and ## length of @var{lenn}. ## ## The optional return value @var{lev} is a vector with the Z values of ## of the contour levels. ## ## Example: ## ## @example ## @group ## x = 0:2; ## y = x; ## z = x' * y; ## contourc (x, y, z, 2:3) ## @result{} 2.0000 2.0000 1.0000 3.0000 1.5000 2.0000 ## 2.0000 1.0000 2.0000 2.0000 2.0000 1.5000 ## @end group ## @end example ## @seealso{contour, contourf, contour3, clabel} ## @end deftypefn ## Author: Shai Ayal <shaiay@users.sourceforge.net> function [cout, lev] = contourc (varargin) if (nargin == 1) vn = 10; z = varargin{1}; [nr, nc] = size (z); x = 1:nc; y = 1:nr; elseif (nargin == 2) vn = varargin{2}; z = varargin{1}; [nr, nc] = size (z); x = 1:nc; y = 1:nr; elseif (nargin == 3) vn = 10; x = varargin{1}; y = varargin{2}; z = varargin{3}; elseif (nargin == 4) vn = varargin{4}; x = varargin{1}; y = varargin{2}; z = varargin{3}; else print_usage (); endif if (!ismatrix (z) || isvector (z) || isscalar (z)) error ("contourc: Z argument must be a matrix"); endif if (isscalar (vn)) vv = linspace (min (z(:)), max (z(:)), vn+2)(2:end-1); else vv = unique (sort (vn)); endif if (isvector (x) && isvector (y)) c = __contourc__ (x(:)', y(:)', z, vv); else ## Indexes x,y for the purpose of __contourc__. ii = 1:columns (z); jj = 1:rows (z); ## Now call __contourc__ for the real work... c = __contourc__ (ii, jj, z, vv); ## Map the contour lines from index space (i,j) back ## to the original grid (x,y) i = 1; while (i < columns (c)) clen = c(2, i); ind = i + [1 : clen]; ci = c(1, ind); cj = c(2,ind); ## due to rounding errors some elements of ci and cj ## can fall out of the range of ii and jj and interp2 would ## return NA for those values. ## The permitted range is enforced here: ci = max (ci, 1); ci = min (ci, columns (z)); cj = max (cj, 1); cj = min (cj, rows (z)); c(1, ind) = interp2 (ii, jj, x, ci, cj); c(2, ind) = interp2 (ii, jj, y, ci, cj); i = i + clen + 1; endwhile endif if (nargout > 0) cout = c; lev = vv; endif endfunction %!test %! x = 0:2; %! y = x; %! z = x' * y; %! [c_actual, lev_actual]= contourc (x, y, z, 2:3); %! c_expected = [2, 1, 1, 2, 2, 3, 1.5, 2; 4, 2, 2, 1, 1, 2, 2, 1.5]; %! lev_expected = [2 3]; %! assert (c_actual, c_expected, eps); %! assert (lev_actual, lev_expected, eps);