How to fit an ecdf to a distribution?

Hello every one, I would appreciate if some body can help me how to fit an ecdf to a distribution?

My code is a cdf Gaussian and I just want to fit an ecdf to the populations. Thank you!

for i=1:lxv
    CG1(i)=(-1/((sqrt(2*pi))*Sn))*exp((-(x(i)-MU)^2)/(2*sig^2));
  end
  CGX=Sn.*(sort(CG1))+Mn; 
  figure (1)
plot(y,CGX,'^b','LineWidth',1);