MATLAB: Where is the error

error using * inner matrix dimensions must agree.matrix dimensions must agree

I'm very new to MATLAB and I'm having alot of trouble debugging this. I need to write an M file that will accept a vector T, and a scalar C (zeta) and return a vector y whose value is defined as,
y=e^(-CT)*(2Ccos(Wd*T)+(We/Wd)*sin(Wd*T))
where Wd=sqrt(1-C^2) and We=1-2C^2 for C=[0,0.2,0.3,0.4,0.5] over the interval T=[0,4pi].
I keep getting the three same messages depending on the changes I make. Either, Matrix dimensions must agree, or error using ".*" or error using "*". Here is my code,
C=[0 0.2 0.3 0.4 0.5];
T=0:0.01:4*pi;
y=exp((-C).*T)*((2*C*cos((sqrt(1-(C^2)).*T)))+(((1-2*(C^2))/(sqrt(1-(C^2))))*sin((sqrt(1-(C^2))).*T)));
y=response(T,C(1));
figure;plot(T,y,'b');hold on
y=response(T,C(2));
plot(T,y,'r');hold on
y=response(T,C(3));
plot(T,y,'k');hold on
y=response(T,C(4));
plot(T,y,'m');hold on
y=response(T,C(5));
plot(T,y,'--b');hold on
I've had help with it but I'm still not able to get it to work. Like I said, I'm very new to this. I've spent hours trying to debug this myself but I just don't know what I'm doing well enough to find the problem.
I can get the desired results from this code but I'm pretty sure that this is not the way they want it to be done, 
T = 0:0.01:4*pi;
y=exp(T*(-0)).*((2*0*cos(T*(sqrt(1-(0^2)))))+(((1-2*(0^2))/(sqrt(1-(0^2)))).*sin(T*(sqrt(1-(0^2))))));
plot (y);hold on
y=exp(T*(-0.2)).*((2*0.2*cos(T*(sqrt(1-(0.2^2)))))+(((1-2*(0.2^2))/(sqrt(1-(0.2^2)))).*sin(T*(sqrt(1-(0.2^2))))));
plot (y);hold on
y=exp(T*(-0.3)).*((2*0.3*cos(T*(sqrt(1-(0.3^2)))))+(((1-2*(0.3^2))/(sqrt(1-(0.3^2)))).*sin(T*(sqrt(1-(0.3^2))))));
plot (y);hold on
y=exp(T*(-0.4)).*((2*0.4*cos(T*(sqrt(1-(0.4^2)))))+(((1-2*(0.4^2))/(sqrt(1-(0.4^2)))).*sin(T*(sqrt(1-(0.4^2))))));
plot (y);hold on
y=exp(T*(-0.5)).*((2*0.5*cos(T*(sqrt(1-(0.5^2)))))+(((1-2*(0.5^2))/(sqrt(1-(0.5^2)))).*sin(T*(sqrt(1-(0.5^2))))));
plot (y);hold on grid on legend('C=0','C=0.2','C=0.3','C=0.4','C=0.5'); ylabel ('y axis') xlabel ('T axis') title ('Graph of y=e^-^C^T(2Ccos(w_dT)+(w_e/w_d)sin(w_dT))')

Best Answer

C is 5 elements long, and T is 1257 elements long, so you can't do (-C).*T because the vector lengths don't match. Perhaps you need loops over both C and T to handle all permutations. Or else use meshgrid() to do it vectorized but that's a little more tricky.
Related Question