problem plotting complex function

Hi everybody! i don't understand why, plotting the complex function eps_compl, separating imag and real part, i obtain always a costant value in frequency, when it should vary with frequency. Besides i'd like to work with a larger range of frequency but it gives me the error "Maximum variable size allowed by the program is exceeded."

the program is this, (i->i^2=-1)

sigma=0.05;

eps_inf=4.0;

eps_cero=8.842*10^(-12);

delta_eps=[47.0 3500 2.5*10^5 3*10^7];

tau=[7.96*10^(-12) 198.94*10^(-9) 79.58*10^(-6) 4.547*10^(-3) ];

alfa=[0.1 0.22 0.22 0];

w=10:.05:10^2;

slen=length(w);

eps_compl=zeros(slen);

for q=1:slen

    for k=1:4

        eps_compl=sigma/(i*w(q)*eps_cero)+eps_inf+(delta_eps(k)/(1+(i*w(q)*tau(k))^(1-alfa(k))));

    end

end

figure(1);

subplot(211); plot(w,real(eps_compl)); title('real impedence');

subplot(212); plot(w,imag(eps_compl)); title('imaginary impedence');

Thank you!

Answer 1

[Mohsen Davarynejad]

The problem is that eps_compl is just a single number, and not an array. You compute eps_compl for every point, but you do not store them. Assign sapce to eps_compl by something like:

eps_compl = ones(q,k) % if the size of eps_compl is q*k

and in your for loop add something like this:

eps_compl(q,k) = ...