Vectors must be the same lengths error

Hi , here is my code.I got this error Vectors must be the same lengths.Can you help me to solve the problem.Thanks. if true format long

tic

N_cut=20;

eps0=(10^-9)/(36*pi);

mu0=4*pi*10^-7;

epsr1=1.;

epsr2=2.;

mur1=1.;

mur2=1.;

eps1=epsr1*eps0;

eps2=epsr2*eps0;

mu1=mur1*mu0;

mu2=mur2*mu0;

freq=6*10^8;

omeg=2*pi*freq;

k=omeg*sqrt(eps1*mu1);

lambda=2*pi/k;

R=0.4;

phi=0;

          for n=1:N_cut
          A=sqrt(pi.*k.*R./2).*besselh(n+0.5,2,k.*R);
          A(isnan(A))=0;
          bes_kur(n)=A;
          B=sqrt(pi.*k.*R./2).*besselh(n+0.5,2,k.*R);
          B(isnan(B))=0;
          han_kur(n)=B;
          C=-n.*sqrt(pi.*k./(2.*R)).*besselj(n+0.5,k.*R)+k.*sqrt(pi.*k.*R./2).*besselj(n-0.5,k.*R);
          C(isnan(C))=0;
          bes_kur_der(n)=C;
          D=-n.*sqrt(pi.*k./(2.*R)).*besselh(n+0.5,2,k.*R)+k.*sqrt(pi.*k.*R./2).*besselh(n-0.5,2,k.*R);
          D(isnan(D))=0;
          han_kur_der(n)=D; 
          a(n)=(1i.^(-n)).*(2.*n+1)./(n.*(n+1));
          b(n)=(-a(n)).*bes_kur_der(n)./han_kur_der(n);
          c(n)=(-a(n)).*bes_kur(n)./han_kur(n);
          end

          for  n=1:N_cut

        L1=legendre(n,cosd(theta));
        L11=legendre(n-1,cosd(theta));
        L2(n,theta)=L1(2,:);
        if n==1
        L3(n,theta)=0.;
        else
        L3(n,theta)=L11(2,:);
        end
        L2_der(n,theta)=(1./(1-(cosd(theta)).^2)).*((-n).*cosd(theta).*L3(n)+((n+1).*L2(n)));
        E_theta(n,theta)=(1i/k*R)*exp(-1i*k*R)*cosd(phi)*((1i.^n).*((b(n).*sind(theta).*L2_der(n,theta)-c(n).*L3(n,theta)./sind(theta))));

          end
          F_Etheta=sum(E_theta,2);
     theta=1:length(F_Etheta):179;
figure
plot(theta,abs(F_Etheta))
grid on
  end

[Tobias]

Does it specify a line inwhich the problem lies?

Answer 1

[Jan]

Please read and post the complete error message. It contains the failing line, which is very useful for solving the problem.

You can use the debugger also:

dbstop if error

Then run the program again. Matlab stops when the error occurs and you can inspect the local variables to find out, which operation is not well defined.

Answer 2

[Walter Roberson]

Why are you using

theta=1:length(F_Etheta):179;

The only way that can be the same length as F_Etheta is if

floor(180/length(F_Etheta)) = length(F_Etheta)

or approximately

179 = length(F_Etheta)^2

so

length(F_Etheta) = sqrt(179)

which is between 13 and 14.

If you experiment with 1:13:179 then its length is 14, and 1:14:179 has length 13, so even if your length happens to be in the right approximate range, it is not possible to match the length of the two vectors.

[Burak]

I want to scale x-axis as thetas and y-axis as F_Etheta , and how can I solve this problem even if I correct it as you told above.