Re: [Help-gsl] IEEE environment variable under Windows

[Chao Ding]

If GSL_IEEE does NOT work in Windows, the initiation of the underflow
in my problem is that, I am computing a beta-binomial probability,
which is
gsl_sf_choose(n, k) * gsl_sf_beta(s+ k, f + n-k) /gsl_sf_beta(s, f);

When s, f get larger, the problem of underflow happens. Is there any
way to get rid of the underflow problem without GSL_IEEE_MODE setting?

Thanks,
Chao



On Wed, Jul 7, 2010 at 2:42 PM, Chao Ding <address@hidden> wrote:
> Thanks Xuebin!
>
> I tried to set an environment variable through "My Computer", and
> there are two different return message depending on the variable value
> setting. I am attaching the setting and corresponding message:
>
> ---------------- (1) -------------
> Variable name: GSL_IEEE_MODE
> Variable value: "mask-underflow"
> message: unrecognized GSL_IEEE_MODE string. valid strings are .....
>
> ---------------- (2) -------------
> Variable name: GSL_IEEE_MODE
> Variable value: mask-underflow
> message: GSL IEEE interface for this platform is not supported or
> could not be determined at configure time
>
> My guess is that the second setting is right, but maybe the GSL_IEEE
> interface does not work in Windows at all. However, from the message
> (1), it seems the system recognizes the GSL_IEEE_MODE variable and
> knows the valid strings.
> If it could work in Windows but just "could not be determined at
> configure time", does anyone know how to set it up in Windows?
>
> If anyone know a certain answer whether the GSL_IEEE interface works
> in Windows, please let me know. Thanks a lot.
>
> Best,
> Chao
>
>
>
>
> On Wed, Jul 7, 2010 at 3:48 AM, Xuebin Wu <address@hidden> wrote:
>> I am not sure if this mechanism works in Windows, but obviously it does not
>> work in your way.
>>
>> In Linux, you need to set the evironment variable in your shell. In Windows,
>> you can set evrionmental variable through the property of "My Computer", but
>> i am not sure if gsl can read it.
>>
>> On Mon, Jul 5, 2010 at 12:13 AM, Chao Ding <address@hidden> wrote:
>>>
>>> Hi there,
>>>
>>> I have two related questions here.
>>>
>>> I am using GSL in Visual C++ 2008 Express under Windows and receive
>>> underflow error handler message. From google, I think the right way to
>>> get rid of it is to set GSL_IEEE_MODE = "mask-underflow", am I right?
>>>
>>> Assume I am right about the way to get rid of the underflow message,
>>> the second problem is that, although I followed the instruction in
>>> Chapter 41 in the manual to set the IEEE environment variable
>>> GSL_IEEE_MODE, but I did not figure out the correct format. I guess it
>>> is a stupid format question but I do not know how. Here is my code:
>>> -------------------------------------------------------------
>>> #include <gsl/gsl_ieee_utils.h>
>>>
>>> void main{
>>>   GSL_IEEE_MODE = "mask-underflow, double-precision, mask-denormalized";
>>>   gsl_ieee_env_setup();
>>>   ....
>>> }
>>> -------------------------------------------------------------
>>> which returns the error message that " 'GSL_IEEE_MODE' : undeclared
>>> identifier" at Building Solution.
>>>
>>> Does anyone how to solve the problem? Thanks a lot!
>>>
>>> Chao
>>>
>>> _______________________________________________
>>> Help-gsl mailing list
>>> address@hidden
>>> http://lists.gnu.org/mailman/listinfo/help-gsl
>>
>>
>