[Boost-bugs] [Boost C++ Libraries] #5095: incorrect results from hypergeometric pdf

Subject: [Boost-bugs] [Boost C++ Libraries] #5095: incorrect results from hypergeometric pdf
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2011-01-19 17:06:00


#5095: incorrect results from hypergeometric pdf
-----------------------------------------+----------------------------------
 Reporter: David Koes <dkoes@…> | Owner: johnmaddock
     Type: Bugs | Status: new
Milestone: To Be Determined | Component: math
  Version: Boost 1.45.0 | Severity: Problem
 Keywords: |
-----------------------------------------+----------------------------------
 #include <boost/math/distributions/hypergeometric.hpp>
 #include <boost/math/policies/policy.hpp>
 #include <iostream>

 using namespace std;
 using namespace boost;

 int main()
 {
   unsigned N = 16086184;
   unsigned n = 256004;
   unsigned Q = 251138;
   math::hypergeometric_distribution<double> hyper(n, Q, N);
   cout << math::pdf<double>(hyper, 4000) << " " <<
 math::pdf<double>(hyper, 4001) << " " << math::pdf<double>(hyper, 4002)
 << "\n";

   return 0;

 }

 Output:
 0.00640003 1.11519e-09 0.00638443
 The value for 4001 is incorrect (according to
 http://stattrek.com/Tables/Hypergeometric.aspx). In fact, every value
 where k is odd appears to be incorrect.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/5095>
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