clc
M = moment(f(:,1),1)
D = moment(f(:,1),2)

P = 0;
sig = vpa(std(f(:,1)),6);
x = -6:0.5:6;
figure
hist(f(:,1),x)
figure 
histfit(f(:,1))
[n,xout] = hist(f(:,1),x);

sigma1 = vpa(sum(n(11:15))/N,6)
sigma2 = vpa(sum(n(9:17))/N,6)
sigma3 = vpa(sum(n(7:19))/N,6)
sigma4 = vpa(sum(n(5:21))/N,6)