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Highlights from
Tutorial on solving DDEs with DDE23

  • exam1
  • exam1
  • exam2
  • exam2
  • exam3
  • exam3
  • exam4
  • exam4
  • exam5
  • exam5
  • exam6 This is a demonstration problem for CTMS/BD in
  • exam6 This is a demonstration problem for CTMS/BD in
  • exam7 An example from C. Marriott and C. DeLisle, Effects
  • exam7 An example from C. Marriott and C. DeLisle, Effects
  • exam8 This is the suitcase problem from Suherman, et al.,
  • exam8 This is the suitcase problem from Suherman, et al.,
  • exer1 Example 1 of K.W. Neves, Automatic integration
  • exer1 Example 1 of K.W. Neves, Automatic integration
  • exer2 Example of J.D. Farmer, Chaotic Attractors of an
  • exer2 Example of J.D. Farmer, Chaotic Attractors of an
  • exer3 Wheldon's model of chronic granuloctic leukemia
  • exer3 Wheldon's model of chronic granuloctic leukemia
  • exer5
  • exer5
  • exer6 Sample problem of ARCHI manual. The absolute error
  • exer6 Sample problem of ARCHI manual. The absolute error
  • exer7 Marchuk immunology model of E. Hairer, S.P. Norsett, and
  • exer7 Marchuk immunology model of E. Hairer, S.P. Norsett, and
  • prob1 This system of ODE's is taken from 'An Introduction to Nuermcial Methods
  • prob1 This system of ODE's is taken from 'An Introduction to Nuermcial Methods
  • prob2 This problem considers a cardiovascular model, which can be found in
  • prob2 This problem considers a cardiovascular model, which can be found in
  • prob2b This problem considers a cardiovascular model, which can be found in
  • prob2b This problem considers a cardiovascular model, which can be found in
  • prob3 This problem is epidemic model due to Cooke, more information can be
  • prob3 This problem is epidemic model due to Cooke, more information can be
  • prob4 This problem is an epidemic model due to Cooke et alia, more information
  • prob4 This problem is an epidemic model due to Cooke et alia, more information
  • prob5 This problem population growth model due to Cooke et alia, more information
  • prob5 This problem population growth model due to Cooke et alia, more information
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Tutorial on solving DDEs with DDE23

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22 Aug 2003 (Updated )

Solving delay differential equations with DDE23. Tutorial + Examples.

exer5
function sol = exer5
% D.R. Wille' and C.T.H. Baker use Example 4 of DELSOL--
% a numerical code for the solution of systems of delay-
% differential equations, Appl. Numer. Math., 9 (992) 
% 223-234 to illustrate a discontinuous history. DDE23 
% treats any order discontinuity in the history as a 
% discontinuity in the solution itself, which is actually 
% the case for this example.

% Copyright 2002, The MathWorks, Inc.

opts = ddeset('Jumps',[-1,-4/5,-3/5,-2/5,-1/5]);
sol = dde23(@exer5f,1,@exer5h,[0, 1],opts);
figure
plot(sol.x,sol.y)
title('Example 4 of Wille'' and Baker.')
xlabel('time t');
ylabel('y(t)');

%-----------------------------------------------------------------------

function yp = exer5f(t,y,Z)
%EXER5F  The derivative function for Exercise 5 of the DDE Tutorial.
yp = Z;

%-----------------------------------------------------------------------

function y = exer5h(t)
%EXER5H  The history function for Exercise 5 of the DDE Tutorial.
y = (-1)^floor(-5*t);

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