[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Bug-gsl] Problem with function gsl_sf_exp in gsl-1.12
From: |
Brian Gough |
Subject: |
Re: [Bug-gsl] Problem with function gsl_sf_exp in gsl-1.12 |
Date: |
Thu, 05 Feb 2009 15:15:49 +0000 |
User-agent: |
Wanderlust/2.14.0 (Africa) Emacs/22.2 Mule/5.0 (SAKAKI) |
At Tue, 3 Feb 2009 13:54:55 +0100,
Pierrick Bruneau wrote:
>
> Hello,
>
> I had little trouble with the function (double) gsl_sf_exp(double) :
> when a pretty low value is passed as parameter (empirically : lower
> than -750.0), this function causes a crash in the calling program.
>
> This is rather surprising as exp is theorically defined for arbitrary
> low values.
> I overcame the problem with a little patch block,
Thanks for your email. The function returns an underflow error
(GSL_EUNDERFLOW) since the result is too small to represent but is not
zero. This is intentional so you can either disable the error handler
or check the argument first in a wrapper function as you've done. The
function gsl_sf_exp_e10_e also has an extended range if you need it.
--
Brian Gough
(GSL Maintainer)
Support freedom by joining the FSF!
http://www.fsf.org/associate/support_freedom/join_fsf?referrer=37