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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 [zt]=BinomialT(n)
function [y]=Binomial(m,n,pb,nb)
// Binomial law (p,N)
// P{X=n} = C_N^n p^n (1-p)^(N-n)
//----------------------------------
res = [];
// we use blocks of size 100 to avoid overflows
ntir = 100;
ntirc = ntir;
y = rand(ntir,nb,"uniform");
indy = find( y < pb);
y = 0*ones(y);
y(indy) = 1;
y = sum(y,"c")
res = [res;y];
while ( ntirc < m*n )
y = rand(ntir,nb,"uniform");
indy = find(y< pb);
y = 0*ones(y);
y(indy) = 1;
y = sum(y,"c")
res = [res;y];
ntirc = ntirc + ntir;
end
y = matrix(res(1:m*n),m,n);
endfunction
[lhs, rhs] = argn(0)
if rhs <= 0 ; n=10000;end
prb = 0.5;
N = 10;
y = Binomial(1, n, prb, N);
i = 0:10;
z = [];
for i1=i, z=[z,prod(size(find(y==i1)))],end
drawlater();
my_handle = scf(100001);
clf(my_handle, "reset");
demo_viewCode("binomial.dem.sce");
plot2d3("onn",i',z'/n,[1,3]);
deff("[y]=fact(n)", "y=prod(1:n)");
deff("[z]=C(N,n)", "z= fact(N)/(fact(n)*fact(N-n))");
i = 0:N;
zt = [];
for j=i, zt=[zt, C(N,j)*prb^j*(1-prb)^(N-j)];end
plot2d1("onn",i',zt',[-2,6]);
xtitle(_("Simulation of a binomial random variable"));
current_axe = gca();
current_axe.title.font_size = 3;
current_axe.background = color(232,230,200);
legend([_("Simulation");_("Theory")]);
drawnow();
endfunction
BinomialT();
clear BinomialT;
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