[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Bug-gsl] [bug #42220] Division by zero in "hybrid*" when initial guess
From: |
Patrick Alken |
Subject: |
[Bug-gsl] [bug #42220] Division by zero in "hybrid*" when initial guess is root |
Date: |
Mon, 28 Apr 2014 15:43:34 +0000 |
User-agent: |
Mozilla/5.0 (X11; Linux i686 on x86_64; rv:28.0) Gecko/20100101 Firefox/28.0 |
URL:
<http://savannah.gnu.org/bugs/?42220>
Summary: Division by zero in "hybrid*" when initial guess is
root
Project: GNU Scientific Library
Submitted by: psa
Submitted on: Mon 28 Apr 2014 03:43:33 PM GMT
Category: Runtime error
Severity: 3 - Normal
Operating System:
Status: None
Assigned to: None
Open/Closed: Open
Release:
Discussion Lock: Any
_______________________________________________________
Details:
Hello GSL team,
The GSL implementations of the "Hybrid" family of multidimensional
rootfinders from MINPACK contain a bug where they divide by zero when the
initial guess happens to be the root. This affects the "fsolver" types
"hybrid" and "hybrids" as well as the "fdfsolver" types "hybridj" and
"hybridsj". This results in a floating point exception if trapping is
enabled.
I have attached a small program (bug_hybrid.c), based on the manual's
example code, that triggers this bug when GSL_IEEE_MODE=trap-common. The
current output is:
GSL_IEEE_MODE="trap-common"
type = hybrid
Floating point exception (core dumped)
The expected output is:
GSL_IEEE_MODE="trap-common"
type = hybrid
status = success
root = 1.000000e+00
type = hybrids
status = success
root = 1.000000e+00
type = hybridj
status = success
root = 1.000000e+00
type = hybridsj
status = success
root = 1.000000e+00
I'll note that when I originally discovered this bug, a colleague of mine
claimed that the problem is not present in the original FORTRAN
implementation in MINPACK, but rather was introduced in the GSL port.
Thank you for looking into this, and if you have any questions, just let me
know.
- Curran
_______________________________________________________
File Attachments:
-------------------------------------------------------
Date: Mon 28 Apr 2014 03:43:33 PM GMT Name: bug_hybrid.c Size: 3kB By: psa
<http://savannah.gnu.org/bugs/download.php?file_id=31266>
_______________________________________________________
Reply to this item at:
<http://savannah.gnu.org/bugs/?42220>
_______________________________________________
Message sent via/by Savannah
http://savannah.gnu.org/
[Prev in Thread] |
Current Thread |
[Next in Thread] |
- [Bug-gsl] [bug #42220] Division by zero in "hybrid*" when initial guess is root,
Patrick Alken <=