Mercurial > octave-libtiff
view scripts/plot/stairs.m @ 2311:2b5788792cad
[project @ 1996-07-11 20:18:38 by jwe]
author | jwe |
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date | Thu, 11 Jul 1996 20:18:38 +0000 |
parents | 5cffc4b8de57 |
children | 5ca126254d15 |
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### Copyright (C) 1996 John W. Eaton ### ### 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 2, 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, write to the Free ### Software Foundation, 59 Temple Place - Suite 330, Boston, MA ### 02111-1307, USA. ## usage: [xs, ys] = stairs (x, y) ## ## Given two vectors of x-y data, stairs produces a `stairstep' plot. ## ## If only one argument is given, it is taken as a vector of y-values ## and the x coordiates are taken to be the indices of the elements. ## ## If two output arguments are specified, the data are generated but ## not plotted. For example, ## ## stairs (x, y); ## ## and ## ## [xs, ys] = stairs (x, y); ## plot (xs, ys); ## ## are equivalent. ## ## See also: plot, semilogx, semilogy, loglog, polar, mesh, contour, ## bar, gplot, gsplot, replot, xlabel, ylabel, title function [xs, ys] = stairs (x, y) if (nargin == 1) if (is_vector (x)) len = 2 * length (x); tmp_xs = tmp_ys = zeros (len, 1); k = 0; for i = 1:2:len tmp_xs(i) = k++; tmp_ys(i) = x(k); tmp_ys(i+1) = x(k); tmp_xs(i+1) = k; endfor else error ("stairs: argument must be a vector"); endif elseif (nargin == 2) if (is_vector (x) && is_vector (y)) xlen = length (x); ylen = length (y); if (xlen == ylen) len = 2 * xlen; tmp_xs = tmp_ys = zeros (len, 1); k = 1; len_m2 = len - 2; for i = 1:2:len_m2 tmp_xs(i) = x(k); tmp_ys(i) = y(k); tmp_ys(i+1) = y(k); k++; tmp_xs(i+1) = x(k); if (x(k) < x(k-1)) error ("stairs: x vector values must be in ascending order"); endif endfor tmp_xs(len-1) = x(xlen); delta = x(xlen) - x(xlen-1); tmp_xs(len) = x(xlen) + delta; tmp_ys(len-1) = y(ylen); tmp_ys(len) = y(ylen); else error ("stairs: arguments must be the same length"); endif else error ("stairs: arguments must be vectors"); endif else usage ("[xs, ys] = stairs (x, y)"); endif if (nargout == 0) plot (tmp_xs, tmp_ys); else xs = tmp_xs; ys = tmp_ys; endif endfunction