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diff --git a/modules/randlib/demos/poisson.dem.sce b/modules/randlib/demos/poisson.dem.sce
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+// Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
+// Copyright (C) ENPC
+// Copyright (C) ????-2008 - INRIA
+// Copyright (C) 2010 - DIGITEO - Allan CORNET
+//
+// This file is released under the 3-clause BSD license. See COPYING-BSD.
+
+
+function [z]=PoissonT(n)
+
+    function [y]=Poisson(m,n,pmean)
+        // P{n} = exp(-lambda)lambda^n/n!
+        // pmean =lambda
+        //----------------------------
+        y=0*ones(m,n)
+        bound= exp(-pmean);
+        for i=1:m*n,
+            count = 0;
+            lprod = 1;
+            while( lprod >= bound), lprod = lprod*rand(1,1,"uniform");
+                count = count + 1;
+            end
+            y(i) = count - 1;
+        end
+        y = matrix(y, m, n);
+    endfunction
+
+
+    [lhs, rhs] = argn(0);
+    if rhs <= 0 ; n = 1000;end
+    pmean = 3;
+    y = Poisson(1, n, pmean);
+    N = 20;
+    i = 0:N;
+    z = [];
+    for i1=i, z=[z,prod(size(find(y==i1)))],end
+
+    drawlater();
+    my_handle = scf(100001);
+    clf(my_handle, "reset");
+    demo_viewCode("poisson.dem.sce");
+
+    plot2d3("onn",i',z'/n,1);
+    deff("[y]=fact(n)","if n==0 then y=1;else y=n*fact(n-1);end");
+    zt=[];for i1=0:N; zt=[zt, exp(-pmean) *pmean^i1/fact(i1)];end
+    plot2d1("onn",i',zt',[-2,6]);
+    xtitle(_("Simulation of a Poisson random variable"));
+    current_axe = gca();
+    current_axe.title.font_size = 3;
+    current_axe.background = color(232,230,200);
+    legend([_("Simulation");_("Theory")]);
+    drawnow();
+
+endfunction
+
+PoissonT();
+clear PoissonT;