Matlab logic of plotting meshgrid formula

There is a code which uses meshgrid which is basicly doing all combination of one vector with the size of the other vector and visa versa. y and z are values of the field in the Y axes and Z axes. In the sum_a_m expression there are .* * / and ./ expresson with the meshgrid Y and Z. What is the logic in that?

Thanks.

y=linspace(-y_lim,y_lim,600);
        z=linspace(-z_lim,z_lim,600);
        [Y,Z]=meshgrid(y,z);
        sum_a_m=0;
        for m=-300:300
           %sum of evanacent wave coefficients
           if(m~=0)
           a_m=-1i*sqrt(k^2-k_t_m^2);
           sum_a_m=sum_a_m+(exp(-1i*(2*pi*m/d)*Y).*exp(-a_m*abs(Z))./a_m);
           end
        end
       
        E_total_2_51=E_0*exp(-1i*k*Y*sin(theta_in)).*exp(-1i*k*Z*cos(theta_in)) ...
        -((eta*I0)/(2*cos(theta_in)*d)).*exp(-1i*k*Y*sin(theta_in)).*exp(-1i*k*abs(Z)*cos(theta_in))...
        -(((1i*k*eta*I0)/(2*d)).*exp(-1i*k.*Y*sin(theta_in)).*sum_a_m);

Answer 1

[Steven Lord]

See this documentation page for a description of the difference between the * and .* operators (and similarly / and ./, etc.)