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[Octave-bug-tracker] [bug #34363] Poor performance for hypergeometric di


From: Lachlan Andrew
Subject: [Octave-bug-tracker] [bug #34363] Poor performance for hypergeometric distributions
Date: Mon, 08 Feb 2016 04:08:51 +0000
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:43.0) Gecko/20100101 Firefox/43.0

Update of bug #34363 (project octave):

                Severity:              3 - Normal => 2 - Minor              
                Priority:              5 - Normal => 3 - Low                
                  Status:         Patch Submitted => None                   
        Operating System:               GNU/Linux => Any                    
                 Summary: Poor performance for certain statistical
distributions => Poor performance for hypergeometric  distributions

    _______________________________________________________

Follow-up Comment #14:

A brief look at the hygeXXX case convinced me that they won't be easy to
vectorise efficiently.  It requires simultaneously working on PDFs of
different lengths.  If each is made a column of a 2D array, then there can be
excessive padding of the short columns.  If they are concatenated to a single
long array, there can be catastrophic loss of precision when taking cumsum.

One approach would be to code these entirely in C++.  A less drastic change
would be to implement a "cumsum with reset points" in C++ and use that.

All supplied patches have been submitted, so I'm changing the status back to
"none", and making the summary specific to hypergeometric distributions.  I'm
also tentatively lowering the severity and priority.

    _______________________________________________________

Reply to this item at:

  <http://savannah.gnu.org/bugs/?34363>

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