Re: [Boost-bugs] [Boost C++ Libraries] #2671: Calculation overflow for the 4th moment

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #2671: Calculation overflow for the 4th moment
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2009-02-04 09:20:56

#2671: Calculation overflow for the 4th moment
-------------------------------------+--------------------------------------
  Reporter:  m.de.wever_at_[hidden]  |       Owner:  eric_niebler
      Type:  Bugs                    |      Status:  new         
 Milestone:  Boost 1.38.0            |   Component:  accumulator 
   Version:  Boost 1.37.0            |    Severity:  Showstopper 
Resolution:                          |    Keywords:              
-------------------------------------+--------------------------------------

Comment(by m.de.wever_at_[hidden]):

 I did some more tests and the 4th moment returns a double when I use
 unsigned as template type. So I still consider it a bug.

 This example, from the library documentation, also leads me to believe the
 result type is a floating point type and it's save to use integer types.
 {{{
 accumulator_set<int, stats<tag::moment<2> > > acc1;

 acc1(2); //    4
 acc1(4); //   16
 acc1(5); // + 25
          // = 45 / 3 = 15

 BOOST_CHECK_CLOSE(15., moment<2>(acc1), 1e-5);
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/2671#comment:2>
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