[Bug-gsl] [bug #43258] confluent hypergeometric functions

[Patrick Alken]

URL:
  <http://savannah.gnu.org/bugs/?43258>

                 Summary: confluent hypergeometric functions
                 Project: GNU Scientific Library
            Submitted by: psa
            Submitted on: Fri 19 Sep 2014 04:17:55 PM GMT
                Category: Runtime error
                Severity: 3 - Normal
        Operating System: 
                  Status: None
             Assigned to: None
             Open/Closed: Open
                 Release: 
         Discussion Lock: Any

    _______________________________________________________

Details:

>From raymond dot rogers72 =at= gmail dot com

If you will check you will find that
hyperg_U.c   fails for U(a,a-1,1)  a>5
hyperg_U.c   fails for U(2,b,1) for b< -2  (with occasional holes due to 
rounding)
These can be checked through gsl-shell, gsl-shell-gui, or I have a 
command line interface.

I believe there is a choke point for the error at the start of 
hyperg_U_series.  There are a couple of sources to it and a couple of 
crashes afterwards.  A fix should be 13.2.8 in DLMF.   I would like to 
discuss this with somebody who has experience with this code before I 
spend much time on the fix.
This should also fix a couple of "unimplemented cases"
I also have a spreadsheet and program comparing test cases from GSL, 
mpmath,  and DAMath; for Confluent Hypergeometric tests.  Not complete 
yet but it 700 (or so) instances.





    _______________________________________________________

Reply to this item at:

  <http://savannah.gnu.org/bugs/?43258>

_______________________________________________
  Message sent via/by Savannah
  http://savannah.gnu.org/