Mercurial > hg > octave-jordi
changeset 20843:75d09edcfc75
codesprint: Move odeplot.m from odepkg to core
* doc/interpreter/diffeq.txi: add DOCSTRING
* scripts/ode/module.mk: include odeplot.m
* scripts/ode/private/: add odeplot.m
author | Stefan Miereis <stefan.miereis@gmx.de> |
---|---|
date | Thu, 10 Dec 2015 02:06:22 +0100 |
parents | f9a0bf346ec1 |
children | 0bb9b4e99ea0 |
files | doc/interpreter/diffeq.txi scripts/ode/module.mk scripts/ode/private/odeplot.m |
diffstat | 3 files changed, 86 insertions(+), 1 deletions(-) [+] |
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--- a/doc/interpreter/diffeq.txi +++ b/doc/interpreter/diffeq.txi @@ -153,6 +153,7 @@ @DOCSTRING(odeget) +@DOCSTRING(odeplot) @node Differential-Algebraic Equations @section Differential-Algebraic Equations
--- a/scripts/ode/module.mk +++ b/scripts/ode/module.mk @@ -12,7 +12,8 @@ scripts/ode/private/ode_struct_value_check.m \ scripts/ode/private/runge_kutta_45_dorpri.m \ scripts/ode/private/runge_kutta_interpolate.m \ - scripts/ode/private/starting_stepsize.m + scripts/ode/private/starting_stepsize.m \ + scripts/ode/private/odeplot.m scripts_ode_FCN_FILES = \ scripts/ode/ode45.m \
new file mode 100644 --- /dev/null +++ b/scripts/ode/private/odeplot.m @@ -0,0 +1,83 @@ +## Copyright (C) 2006-2015 Thomas Treichl <treichl@users.sourceforge.net> +## +## 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/>. + +## Author: Thomas Treichl <treichl@users.sourceforge.net> + +%# -*- texinfo -*- +%# @deftypefn {Function File} {[@var{ret}] =} odeplot (@var{t}, @var{y}, @var{flag}) +%# +%# Open a new figure window and plot the results from the variable @var{y} of type column vector over time while solving. The types and the values of the input parameter @var{t} and the output parameter @var{ret} depend on the input value @var{flag} that is of type string. If @var{flag} is +%# @table @option +%# @item @code{"init"} +%# then @var{t} must be a double column vector of length 2 with the first and the last time step and nothing is returned from this function, +%# @item @code{""} +%# then @var{t} must be a double scalar specifying the actual time step and the return value is false (resp. value 0) for 'not stop solving', +%# @item @code{"done"} +%# then @var{t} must be a double scalar specifying the last time step and nothing is returned from this function. +%# @end table +%# +%# This function is called by a ode solver function if it was specified in an options structure with the @command{odeset}. This function is an internal helper function therefore it should never be necessary that this function is called directly by a user. There is only little error detection implemented in this function file to achieve the highest performance. +%# +%# For example, solve an anonymous implementation of the "Van der Pol" equation and display the results while solving +%# @example +%# fvdb = @@(t,y) [y(2); (1 - y(1)^2) * y(2) - y(1)]; +%# +%# opt = odeset ("OutputFcn", @@odeplot, "RelTol", 1e-6); +%# sol = ode45 (fvdb, [0 20], [2 0], opt); +%# @end example +%# @end deftypefn +%# +%# @seealso{odepkg} + +function [varargout] = odeplot (t, y, flag, varargin) + + ## No input argument check is done for a higher processing speed + persistent fig; persistent told; + persistent yold; persistent counter; + + if (strcmp (flag, "init")) + ## Nothing to return, t is either the time slot [tstart tstop] + ## or [t0, t1, ..., tn], y is the inital value vector "init" + fig = figure; told = t(1,1); yold = y(:,1); + counter = 1; + + elseif (isempty (flag)) + ## Return something in varargout{1}, either false for "not stopping + ## the integration" or true for "stopping the integration" + counter = counter + 1; figure (fig); + told(counter,1) = t(1,1); + yold(:,counter) = y(:,1); + plot (told, yold, "-o", "markersize", 1); drawnow; + varargout{1} = false; + + elseif (strcmp (flag, "done")) + ## Cleanup has to be done, clear the persistent variables because + ## we don't need them anymore + clear ("figure", "told", "yold", "counter"); + + endif + +endfunction + + +%!demo +%! % solve an anonymous implementation of the "Van der Pol" equation +%! % and display the results while solving +%! fvdb = @(t,y) [y(2); (1 - y(1)^2) * y(2) - y(1)]; +%! opt = odeset ("OutputFcn", @odeplot, "RelTol", 1e-6); +%! sol = ode45 (fvdb, [0 20], [2 0], opt);