how to find sinusoidal wave form using exponential?

i have a code for sinusoidal fringe pattern but i need wave form my code:

% sinusoidal fringe pattern
m=1000;
n=1000;
f1=20;  % No. of vertical fringes
f2=0;  % No. of horizontal fringes
for i=1:m
    for j=1:n   

          I(i,j)=exp(1i*(2*pi*(f1*j/n+f2*i/m)));

      end
  end
  imshow(I,[])