Forced Van der Pol... ODE help... Update function - Programmers Heaven

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# Forced Van der Pol... ODE help... Update function

Posts: 1Member
Hi i've looked for help with this problem all over but found little to no help.

I'm simply trying to model a forced Van der Pol oscillator (ie instead of making diff equation = 0 now make it =cos(wt)). I need to update my function "vdp" 's 't' term as i run the code. I don't see how i can do this (ie i want the t term in the cos function to increment for each execution). Please any help would be greatly appreciated.

My code:
vdp file:

function dydt = vdp(t,y,Mu)
dydt =[y(2);Mu*(1-y(1)^2)*y(2)-y(1)+Mu*(sin(800*pi*t)+sin(900*pi*t))];
% End solvevdp.m

test file:
t = [1:100:1]
Mu= 1000;

ode= @(t,y) vdp(t,y,Mu);
[t,y]=ode23(ode,[0, 3000],[2;0]);

plot(t,y(:,1))
title('van der Pol Equation, mu = 1000')
axis([0 3000 -3 3])
xlabel('t')
ylabel('solution y')