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comparison scripts/ode/private/odepkg_event_handle.m @ 20568:fcb792acab9b

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Moving ode45, odeset, odeget, and levenshtein from odepkg to core. * libinterp/corefcn/levenshtein.cc: move function from odepkg into core * libinterp/corefcn/module.mk: include levenshtein.cc * scripts/ode: move ode45, odeset, odeget, and all dependencies from odepkg into core * scripts/module.mk: include them * doc/interpreter/diffeq.txi: add documentation for ode45, odeset, odeget * NEWS: announce functions included with this changeset * scripts/help/__unimplemented__.m: removed new functions
author jcorno <jacopo.corno@gmail.com>
date Thu, 24 Sep 2015 12:58:46 +0200
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children 6256f6e366ac
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20567:2480bbcd1333 20568:fcb792acab9b
1 %# Copyright (C) 2006-2012, Thomas Treichl <treichl@users.sourceforge.net>
2 %# OdePkg - A package for solving ordinary differential equations and more
3 %#
4 %# This program is free software; you can redistribute it and/or modify
5 %# it under the terms of the GNU General Public License as published by
6 %# the Free Software Foundation; either version 2 of the License, or
7 %# (at your option) any later version.
8 %#
9 %# This program is distributed in the hope that it will be useful,
10 %# but WITHOUT ANY WARRANTY; without even the implied warranty of
11 %# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 %# GNU General Public License for more details.
13 %#
14 %# You should have received a copy of the GNU General Public License
15 %# along with this program; If not, see <http://www.gnu.org/licenses/>.
16
17 %# -*- texinfo -*-
18 %# @deftypefn {Function File} {[@var{sol}] =} odepkg_event_handle (@var{@@fun}, @var{time}, @var{y}, @var{flag}, [@var{par1}, @var{par2}, @dots{}])
19 %#
20 %# Return the solution of the event function that is specified as the first input argument @var{@@fun} in form of a function handle. The second input argument @var{time} is of type double scalar and specifies the time of the event evaluation, the third input argument @var{y} either is of type double column vector (for ODEs and DAEs) and specifies the solutions or is of type cell array (for IDEs and DDEs) and specifies the derivatives or the history values, the third input argument @var{flag} is of type string and can be of the form
21 %# @table @option
22 %# @item @code{"init"}
23 %# then initialize internal persistent variables of the function @command{odepkg_event_handle} and return an empty cell array of size 4,
24 %# @item @code{"calc"}
25 %# then do the evaluation of the event function and return the solution @var{sol} as type cell array of size 4,
26 %# @item @code{"done"}
27 %# then cleanup internal variables of the function @command{odepkg_event_handle} and return an empty cell array of size 4.
28 %# @end table
29 %# Optionally if further input arguments @var{par1}, @var{par2}, @dots{} of any type are given then pass these parameters through @command{odepkg_event_handle} to the event function.
30 %#
31 %# This function is an OdePkg 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.
32 %# @end deftypefn
33 %#
34 %# @seealso{odepkg}
35
36 function [vretval] = odepkg_event_handle (vevefun, vt, vy, vflag, varargin)
37
38 %# No error handling has been implemented in this function to achieve
39 %# the highest performance available.
40
41 %# vretval{1} is true or false; either to terminate or to continue
42 %# vretval{2} is the index information for which event occured
43 %# vretval{3} is the time information column vector
44 %# vretval{4} is the line by line result information matrix
45
46 %# These persistent variables are needed to store the results and the
47 %# time value from the processing in the time stamp before, veveold
48 %# are the results from the event function, vtold the time stamp,
49 %# vretcell the return values cell array, vyold the result of the ode
50 %# and vevecnt the counter for how often this event handling
51 %# has been called
52 persistent veveold; persistent vtold;
53 persistent vretcell; persistent vyold;
54 persistent vevecnt;
55
56 %# Call the event function if an event function has been defined to
57 %# initialize the internal variables of the event function an to get
58 %# a value for veveold
59 if (strcmp (vflag, 'init'))
60
61 if (~iscell (vy))
62 vinpargs = {vevefun, vt, vy};
63 else
64 vinpargs = {vevefun, vt, vy{1}, vy{2}};
65 vy = vy{1}; %# Delete cell element 2
66 end
67 if (nargin > 4)
68 vinpargs = {vinpargs{:}, varargin{:}};
69 end
70 [veveold, vterm, vdir] = feval (vinpargs{:});
71
72 %# We assume that all return values must be column vectors
73 veveold = veveold(:)'; vterm = vterm(:)'; vdir = vdir(:)';
74 vtold = vt; vyold = vy; vevecnt = 1; vretcell = cell (1,4);
75
76 %# Process the event, find the zero crossings either for a rising
77 %# or for a falling edge
78 elseif (isempty (vflag))
79
80 if (~iscell (vy))
81 vinpargs = {vevefun, vt, vy};
82 else
83 vinpargs = {vevefun, vt, vy{1}, vy{2}};
84 vy = vy{1}; %# Delete cell element 2
85 end
86 if (nargin > 4)
87 vinpargs = {vinpargs{:}, varargin{:}};
88 end
89 [veve, vterm, vdir] = feval (vinpargs{:});
90
91 %# We assume that all return values must be column vectors
92 veve = veve(:)'; vterm = vterm(:)'; vdir = vdir(:)';
93
94 %# Check if one or more signs of the event has changed
95 vsignum = (sign (veveold) ~= sign (veve));
96 if (any (vsignum)) %# One or more values have changed
97 vindex = find (vsignum); %# Get the index of the changed values
98
99 if (any (vdir(vindex) == 0))
100 %# Rising or falling (both are possible)
101 %# Don't change anything, keep the index
102 elseif (any (vdir(vindex) == sign (veve(vindex))))
103 %# Detected rising or falling, need a new index
104 vindex = find (vdir == sign (veve));
105 else
106 %# Found a zero crossing but must not be notified
107 vindex = [];
108 end
109
110 %# Create new output values if a valid index has been found
111 if (~isempty (vindex))
112 %# Change the persistent result cell array
113 vretcell{1} = any (vterm(vindex)); %# Stop integration or not
114 vretcell{2}(vevecnt,1) = vindex(1,1); %# Take first event found
115 %# Calculate the time stamp when the event function returned 0 and
116 %# calculate new values for the integration results, we do both by
117 %# a linear interpolation
118 vtnew = vt - veve(1,vindex) * (vt - vtold) / (veve(1,vindex) - veveold(1,vindex));
119 vynew = (vy - (vt - vtnew) * (vy - vyold) / (vt - vtold))';
120 vretcell{3}(vevecnt,1) = vtnew;
121 vretcell{4}(vevecnt,:) = vynew;
122 vevecnt = vevecnt + 1;
123 end %# if (~isempty (vindex))
124
125 end %# Check for one or more signs ...
126 veveold = veve; vtold = vt; vretval = vretcell; vyold = vy;
127
128 elseif (strcmp (vflag, 'done')) %# Clear this event handling function
129 clear ('veveold', 'vtold', 'vretcell', 'vyold', 'vevecnt');
130 vretcell = cell (1,4);
131
132 end
133
134 %# Local Variables: ***
135 %# mode: octave ***
136 %# End: ***