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Topic: Logistic equation with delay
Replies: 8   Last Post: Mar 24, 2014 3:42 AM

 Messages: [ Previous | Next ]
 Sankar Posts: 4 Registered: 3/20/14
Re: Logistic equation with delay
Posted: Mar 21, 2014 8:49 AM

"Torsten" wrote in message <lggr8s\$dj8\$1@newscl01ah.mathworks.com>...
> "Adin" wrote in message <lggbgg\$95h\$1@newscl01ah.mathworks.com>...
> > 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 ?
>
> Best wishes
> Torsten.

Oh, I thought I was solving for the continuous logistic equation with delay on the last part but I guess not....what do I have to add/change to do that then?

Date Subject Author
3/20/14 Sankar
3/21/14 Torsten
3/21/14 Sankar
3/21/14 Torsten
3/21/14 Sankar
3/21/14 Torsten
3/21/14 Steven Lord
3/21/14 Sankar
3/24/14 Torsten