"Adin" wrote in message <firstname.lastname@example.org>... > I am trying to solve a logistic equation with delay WITHOUT using dde23. So the delay is of the form: ddtN(t)=N(t)(a-bN(t-?t)),a>0,b>0 > > I have a function called logistic that looks like this: > function dN = logistic(t,N) > global a b; > dN = (a-N.*b)*N; > > And another file that calls this function with ode45 like this: > global a b; > a = 4; > b = 1; > [t, N] = ode45('logistic', [0:.01:5], 10); > >
ok, here you try to solve the _continuous_ logistic equation without delay.
> I think I understand how to write a for-loop to calculate the logistic equation with delay of 1 since I'm picking my ? to be 1; but I'm not getting the correct results. Here is the code: > S=zeros(501,1); > t=zeros(501,1); > S(1)=0; > > for iterate=1:501 > S(i) = S(i-1) + r*S(i-1)*(1-b*S(i-1)) > end > plot(t,S) >
ok, here you try to solve the _discrete_ logistic equation without delay (although the case S(1)=0 is not that interesting)
> > Any ideas?
And where do you try to solve the continuous logistic equation with delay ?