Hi,
Thank you for your answers.
In fact, my question is about the width of "double precision" (64, 128 or
more bits ?)
Note : amber 8 , sander , ramd
Station : Intel(R) Pentium(R) 4 CPU 3.20GHz
Best regards,
Sophie
2010/5/1 Robert Duke <rduke.email.unc.edu>
> All of pmemd just uses "double precision" instead of "real". The use of
> "double precision" is I think deprecated in the latest fortran standards,
> but it is really clear what you are doing, and they may deprecate the usage,
> but it is unlikely to go away, given the wide use. The whole "kind" system
> focuses on the range of values you can represent, which certainly is
> mathematically useful. But for a lot of computer-related issues, it is
> actually (at least to me) also useful to know how much storage is required.
> The two are related, but not precisely - depends on the exact nature of the
> number representation, especially for floating point, and also I think that
> there is an "at least" sense to "kind", so the compiler maker can just use
> more storage than required to represent a specified range.
> Regards - Bob Duke
> ----- Original Message ----- From: "Jason Swails" <jason.swails.gmail.com>
> To: "AMBER Mailing List" <amber.ambermd.org>
> Sent: Saturday, May 01, 2010 10:25 AM
> Subject: Re: [AMBER] size of real
>
>
>
> Hello,
>>
>> On Sat, May 1, 2010 at 9:03 AM, sop dadoun <dadoun.sop.gmail.com> wrote:
>>
>> Dear amber users,
>>>
>>> I would like to know the size of real for a fortran program used in amber
>>> with Pentium 4 CPU.
>>>
>>>
>> Most amber programs include the file $AMBERHOME/include/dprec.h or .fh,
>> depending on what version of amber you're talking about. The precision of
>> _REAL_ depends on the preprocessor flags that are given to (u)cpp.
>> Typically, though, they're double unless you modify something.
>>
>> All the best,
>> Jason
>>
>> Thanks you for rplying
>>
>>> Best regards,
>>> Sophie
>>> _______________________________________________
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>>> AMBER.ambermd.org
>>> http://lists.ambermd.org/mailman/listinfo/amber
>>>
>>>
>>
>>
>> --
>> Jason M. Swails
>> Quantum Theory Project,
>> University of Florida
>> Ph.D. Graduate Student
>> 352-392-4032
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>> AMBER mailing list
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>> http://lists.ambermd.org/mailman/listinfo/amber
>>
>>
>>
>
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Received on Sat May 01 2010 - 15:30:03 PDT
