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aniket
Posts:
23
Registered:
1/15/13


How should I plot error graph ?
Posted:
Feb 5, 2013 1:41 PM


Hello,
I have implemented adaptive hopf oscillator with ode45 solver. This oscillator adapts the frequency of external input signal. Now i want to plot error graph between input frequency and output frequency
i.e E = Win  Wout
Win = external input frquency
Wout = adapted frequency by oscillator
**********************
function dz = myeqd(t,y,ti,fi)
dz = zeros(3,1);
mu=0.7;
r= sqrt(y(1)^2 + y(2)^2);
K=2;
F=interp1(ti,fi,t);
dz(1)= (mu  r^2)*y(1)  y(3)*y(2) +K*F;
dz(2) = (mu  r^2)*y(2) + y(3)*y(1);
dz(3) = (K*F) * (y(2)/sqrt(y(1)^2 + y(2)^2));
********************************
then call this function
******************************
Tspan= 0:0.01:500; % time vector
fi = cos(10*Tspan); % external perturbation
ti=Tspan;
[T,Y]=ode45(@(t,y) myeqd(t,y,ti,fi),Tspan,[1;1;30]);
plot (T,Y(:,3))
************************************************
here fi is external input signal.
and In function y(3) is internal frequency of oscillator and it is adapted to external frequency. I want to plot error graph for this.
K is coupling strength ... (if it is high adaptation is quicker)
this error graph maybe with respect to parameter value K or i think with respect to time ?
How should i do this ?
Thank You



