function [x_sigma, x_gam] = gaussian_para_esti(x)
% x = x(:);
gam = 0.2:0.001:10;
r_gam = (gamma(1./gam).*gamma(3./gam))./((gamma(2./gam)).^2);
x_mu = mean(x);
x_sigma_sq = mean((x - x_mu).^2);
x_sigma = sqrt(x_sigma_sq);
E_x = mean(abs(x - x_mu));
rho_x = x_sigma_sq/E_x^2;
[x_diff, x_ind] = min(abs(rho_x - r_gam));
x_gam = gam(x_ind);  
