calculate the variance account

i am new to matllab, below is the given code, i tried to run it but i think i am missing something

t= 0:0.001:3;

xref = sin(2*pi*t).*cos(2*pi*t);

xs1 = 0.5*sin(2*pi*t).*cos(2*pi*t);

xs2 = 1.0*sin(2*pi*t).*cos(2*pi*t);

xs3 = 1.0*sin(2*pi*t).*cos(2*pi*t)+0.1*sin(2*pi*10*t);

[David Wilson]

Not really clear what the problem is. Do you want to regenerate the plot?

t= [0:0.001:3]'; % changed to column vector. 
 xref = sin(2*pi*t).*cos(2*pi*t);
 xs1 = 0.5*sin(2*pi*t).*cos(2*pi*t);
 xs2 = 1.0*sin(2*pi*t).*cos(2*pi*t); 
xs3 = 1.0*sin(2*pi*t).*cos(2*pi*t)+0.1*sin(2*pi*10*t);

subplot(3,1,1); 
plot(t,[xref, xs1])
subplot(3,1,2); 
plot(t,[xref, xs2])
subplot(3,1,3); 
plot(t,[xref, xs3])

[amin assadi]

figure;

subplot(3,1,1);

plot(t,[xref; xs1])

subplot(3,1,2);

plot(t,[xref; xs2])

subplot(3,1,3);

plot(t,[xref; xs3])