Exponential distribution illustration

% c6exp.m - Chapter 6: exponential distribution illustration

help c6exp

disp('This M-file illustrates 3 probability distributions...')


rand('seed',0); n=20000; % Reset the 'seed' value
m=1।2; s=1।2; % mean and std
x = unirand(0,2।4,n,1); % Uniform in (0,2।4)
randn('seed',0); % Reset the 'seed' value
y = normrand(m,s,n,1); % Normal N(1।2,1।2)


rand('seed',0); % Reset the 'seed' value
z = exprand(m,n,1); % Exponential



subplot(311); hist(x,90) % Plot x
axis([0 2।4 0 225]) % Cut the right half

hold on; plot([m m],[0 225],':r'); hold off

subplot(312); hist(y,20) % Plot y
hold on; plot([m m],[0 4000],':r'); hold off



subplot(313); hist(z,40)% Plot z

axis([0 10 0 6852]) % Cut the right half

hold on; plot([m m],[0 6852],':r'); hold off



%%% The following lines are for "cumsum" %%%

t=cumsum(z);

fprintf('For n = %d, t first and last = %10.4f, %10.4f\n',n,t(1),t(n));

format compact; tm=hist(z,40); sum(tm);tm=max(tm)