Search All of the Math Forum:
Views expressed in these public forums are not endorsed by
NCTM or The Math Forum.


aniket
Posts:
23
Registered:
1/15/13


trying to plot difference between input frequency and estimated frequency ?
Posted:
Feb 6, 2013 6:00 AM


hello ,
I want to plot a graph of difference between input signal frequency and adapted frequency . how should i do it ?
here is my code
in this,
fin is input signal frequency
y(3) mention in function is oscillator initial frequency
dz(3) mention in function is learning rule for oscillator frequency, because of this oscillator adapts input signal frequency.
i want to plot difference of fin and dz(3)
for example D = fin  dz(3)
**********************
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
fin = 10;
fi = cos(fin*Tspan); % external perturbation
ti=Tspan;
[T,Y]=ode45(@(t,y) myeqd(t,y,ti,fi),Tspan,[1;1;30]);
plot (T,Y(:,3))
************************************************



