Re: [Boost-bugs] [Boost C++ Libraries] #7177: Students t returns rubbihs values for undefined input instead of throw

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #7177: Students t returns rubbihs values for undefined input instead of throw
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2012-08-02 08:59:16


#7177: Students t returns rubbihs values for undefined input instead of throw
--------------------------------------+-------------------------------------
  Reporter: pbristow | Owner: pbristow
      Type: Bugs | Status: closed
 Milestone: Boost 1.52.0 | Component: math
   Version: Boost Development Trunk | Severity: Problem
Resolution: fixed | Keywords: math students t
--------------------------------------+-------------------------------------
Changes (by pbristow):

  * status: new => closed
  * version: Boost 1.50.0 => Boost Development Trunk
  * resolution: => fixed

Comment:

 After much discussion, we decided to make all moments when df =< moment
 index k throw domain error (and return NaN is the throw is ignored by a
 policy).

 Sources are unclear on this, Wikipedia claiming variance should be ∞ for 1
 < \nu ≤ 2, etc.
 but this probably only applies if df is integral and this package allows
 real values.

 And no practical use of having a return of infinity rather than NaN was
 proposed.

 So, in the absence of a good case, we have Kept It Simple Sirs and
 returned quiet_NaN.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/7177#comment:1>
Boost C++ Libraries <http://www.boost.org/>
Boost provides free peer-reviewed portable C++ source libraries.

This archive was generated by hypermail 2.1.7 : 2017-02-16 18:50:10 UTC