Mercurial > octave-libtiff
view scripts/ode/odeplot.m @ 30564:796f54d4ddbf stable
update Octave Project Developers copyright for the new year
In files that have the "Octave Project Developers" copyright notice,
update for 2021.
In all .txi and .texi files except gpl.txi and gpl.texi in the
doc/liboctave and doc/interpreter directories, change the copyright
to "Octave Project Developers", the same as used for other source
files. Update copyright notices for 2022 (not done since 2019). For
gpl.txi and gpl.texi, change the copyright notice to be "Free Software
Foundation, Inc." and leave the date at 2007 only because this file
only contains the text of the GPL, not anything created by the Octave
Project Developers.
Add Paul Thomas to contributors.in.
author | John W. Eaton <jwe@octave.org> |
---|---|
date | Tue, 28 Dec 2021 18:22:40 -0500 |
parents | 7854d5752dd2 |
children |
line wrap: on
line source
######################################################################## ## ## Copyright (C) 2006-2022 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{stop_solve} =} odeplot (@var{t}, @var{y}, @var{flag}) ## ## Open a new figure window and plot the solution of an ode problem at each ## time step during the integration. ## ## The types and values of the input parameters @var{t} and @var{y} depend on ## the input @var{flag} that is of type string. Valid values of @var{flag} ## are: ## ## @table @option ## @item @qcode{"init"} ## The input @var{t} must be a column vector of length 2 with the first and ## last time step (@code{[@var{tfirst} @var{tlast}]}. The input @var{y} ## contains the initial conditions for the ode problem (@var{y0}). ## ## @item @qcode{""} ## The input @var{t} must be a scalar double specifying the time for which ## the solution in input @var{y} was calculated. ## ## @item @qcode{"done"} ## The inputs should be empty, but are ignored if they are present. ## @end table ## ## @code{odeplot} always returns false, i.e., don't stop the ode solver. ## ## Example: solve an anonymous implementation of the ## @nospell{@qcode{"Van der Pol"}} equation and display the results while ## solving. ## ## @example ## @group ## fvdp = @@(t,y) [y(2); (1 - y(1)^2) * y(2) - y(1)]; ## ## opt = odeset ("OutputFcn", @@odeplot, "RelTol", 1e-6); ## sol = ode45 (fvdp, [0 20], [2 0], opt); ## @end group ## @end example ## ## Background Information: ## This function is called by an ode solver function if it was specified in ## the @qcode{"OutputFcn"} property of an options structure created with ## @code{odeset}. The ode solver will initially call the function with the ## syntax @code{odeplot ([@var{tfirst}, @var{tlast}], @var{y0}, "init")}. The ## function initializes internal variables, creates a new figure window, and ## sets the x limits of the plot. Subsequently, at each time step during the ## integration the ode solver calls @code{odeplot (@var{t}, @var{y}, [])}. ## At the end of the solution the ode solver calls ## @code{odeplot ([], [], "done")} so that odeplot can perform any clean-up ## actions required. ## @seealso{odeset, odeget, ode23, ode45} ## @end deftypefn function stop_solve = odeplot (t, y, flag) ## No input argument checking is done for better performance persistent hlines num_lines told yold; ## odeplot never stops the integration stop_solve = false; if (isempty (flag)) ## Default case, plot and return a value told = [told; t(:)]; yold = [yold, y]; for i = 1:num_lines set (hlines(i), "xdata", told, "ydata", yold(i,:)); endfor drawnow (); retval = false; elseif (strcmp (flag, "init")) ## t is either the time slot [tstart tstop] or [t0, t1, ..., tn] ## y is the initial value vector for the ode solution told = t(1); yold = y(:); figure (); hlines = plot (told, yold, "o-"); xlim ([t(1), t(end)]); # Fix limits which also speeds up plotting num_lines = numel (hlines); elseif (strcmp (flag, "done")) ## Cleanup after ode solver has finished. hlines = num_lines = told = yold = []; endif endfunction %!demo %! ## Solve an anonymous implementation of the Van der Pol equation %! ## and display the results while solving %! fvdp = @(t,y) [y(2); (1 - y(1)^2) * y(2) - y(1)]; %! opt = odeset ("OutputFcn", @odeplot, "RelTol", 1e-6); %! sol = ode45 (fvdp, [0 20], [2 0], opt);