// <pre>
// expo.sce
clear;
clf;
rand("uniform");    


lambda = 1.0;
N = 1600;
a = 0.0;
b = 5.0;


x = a:0.01:b;
densite = lambda*exp(-lambda*x);
plot2d(x, densite, 5);  // 5 couleur rouge

s = a:0.20:b;
data = - log( rand(1,N) )/lambda;
histplot(s, data);