Code covered by the BSD License  

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
  • View all files

Tutorial on solving DDEs with DDE23

by

 

22 Aug 2003 (Updated )

Solving delay differential equations with DDE23. Tutorial + Examples.

prob3
function sol = prob3
%  This problem is epidemic model due to Cooke, more information can be
%  found in 'Time lags in Biological Models', by N. MacDonald.  (This is
%  reference 8 of the tutorial).

% Copyright 2004, The MathWorks, Inc.

  % Problem parameters, visible in nested functions.
  b = 2;
  c = 1;
  e = 1 - c/b;   % Equilibrium point.

  sol = dde23(@prob3f,7,0.8,[0, 60]);

  figure
  plot(sol.x,sol.y,[0, 60],[e, e],'r')
  legend('y(t)','1 - c/b')
  title(['Problem 3. Cooke Epidemic Model with' ...
         ' b = ',num2str(b),' , c = ',num2str(c),'.'])
  xlabel('time t')
  
  %-----------------------------------------------------------------------
  % Nested function
  %
  
  function yp = prob3f(t,y,Z)
  %PROB3F  The derivative function for Problem 3 of the DDE Tutorial.
    yp = b * Z * (1 - y) - c * y;
  end % prob3f

  %-----------------------------------------------------------------------
  
end  % prob3  

Contact us