In an assignment A(I) = B, the number of elements in B and I must be the same.

Hi everyone, Here is the code, that gives me the error that I put in my title. Please correct my code, Also, I am new in MATLAB, so if you see better way to do my work, please advice me Thanks in advance

syms t

x=-3:.1:3;

for i=1:length(x);

    Pin=3*exp(-t^2);

    z=x(i);

    Eo(i)=int(Pin,t,-inf,z);

    Ein(i)=int(Pin,t,-inf,inf);

    E(i)=double(Eo (i)/Ein(i));

    Go=1000;

    G(i)=Go/(Go-(Go-1)*exp(-E(i)*0.1));

    Pin=3*exp(-x(i)^2);

    Pout(i)=Pin*G(i);

    Bc=5;

    Phi(i)=-0.5*Bc*log(G(i))*pi/180;

    Aout(i)=sqrt(Pout(i))*exp(i*Phi(i));
end

Aoutf=fftshift(fft(Aout,100000));

f=(-100000/2:(100000/2-1)).*1/(0.01*100000);

Poutf(i)=abs (Aoutf).^2;

plot(f,abs(Poutf),'-r*')

Answer 1

[Paulo Silva]

syms t

x=-3:.1:3;

for i=1:length(x);
    Pin=3*exp(-t^2);
    z=x(i);
    Eo(i)=int(Pin,t,-inf,z);
    Ein(i)=int(Pin,t,-inf,inf);
    E(i)=double(Eo (i)/Ein(i));
    Go=1000;
    G(i)=Go/(Go-(Go-1)*exp(-E(i)*0.1));
    Pin=3*exp(-x(i)^2);
    Pout(i)=Pin*G(i);
    Bc=5;
    Phi(i)=-0.5*Bc*log(G(i))*pi/180;
    Aout(i)=sqrt(Pout(i))*exp(i*Phi(i));
end

Aoutf=fftshift(fft(Aout,100000));

f=(-100000/2:(100000/2-1)).*1/(0.01*100000);

Poutf=abs (Aoutf).^2;  %no (i) needed here

plot(f,abs(Poutf),'-r*')

[Paulo Silva]

I don't know if the code is correct, just fixed the error, the line you had with Poutf(i)=abs (Aoutf).^2; was wrong because i in that line is equal to length(x), it's just a value so Poutf(i) can only hold one value and the expression in front of the equal sign returns several values, thus the error you got. Without the (i) that variable Poutf can hold almost whatever you want.