MATLAB: Subscripted assignment dimension mismatch. what does it mean

Question

clc;
clear;
close all;
k=3;
for i=1:k
    fi= input('\nEnter spatial frequency: f(i)=');
        f=0:0.01:1;
        fo=0:0.01:1;
        m=0:0.3:30;
        mo=0:0.3:30;
        fx=0.2;
        fy=0.2;
        rho=0.02;
        sd=zeros(length(f),length(fo));
        s=zeros(length(m),length(mo));
        find=1;
        foind=1;
        mind=1;
        moind=1;
for F=f
     for Fo=fo
         if ((F==fi)&&(Fo==fi))
                  sk(find,foind)=1;
              else
                  sk(find,foind)=0;
         end
             g(find,foind)=(1/(fx*fy*sqrt(1-rho^2)))*exp((-1/(2*(1-rho^2)))*((F^2/fx^2)-((2*rho*F*Fo)/(fx*fy))-(Fo^2/fy^2)))/(fx.*fy.*sqrt(1-rho.^2));
         sd(find,foind)=sd(find,foind)+conv(sk(find,foind),g(find,foind));      
foind=foind+1;
     end
     find=find+1;
     foind=1;
end
 for l=1:k
         s(mind,moind)=(1/k^2)*(s(mind,moind)+(sd(i/k,l/k)*exp(-j*2*pi*((i*m/k)-(l*mo/k)))));
         moind=moind+1;
         end
mind=mind+1;
moind=1;
   end
mesh(f,fo,s);
hold on;
xlabel('\bff');
ylabel('\bffo');
zlabel('\bfs(m,mo)');

Answer 1

Time for you to learn how to use the debugger. At the command line give the command

dbstop if error

and then run the program. When it stops with the error, examine the size() of each of the indices on the left hand side of the assignment statement, and the size() of the expression that you are trying to assign (that is, the size() of the right hand side of the assignment statement)