chi-squared distribution

close all; clear all;

x = 0:0.2:100;

y = chi2pdf(x,38);

figure;

plot(x,y)

ylabel('Probability density');

xlabel('Chi-squared value');

% calculate chi-squared value over specific probability

% under specified degree of freedom

X_05 = chi2inv(0.95,38)

X_01 = chi2inv(0.99,38)

X_001 = chi2inv(0.999,38)

show = ['Chi-squared 0.05: ', num2str(X_05)];

text(60, 0.03, show);

show = ['Chi-squared 0.01: ', num2str(X_01)];

text(60, 0.025, show);

show = ['Chi-squared 0.001: ', num2str(X_001)];

text(60, 0.020, show);

title('Chi-squared distribution dof=38')