32 bit or 64 bit?

Mensanator mensanator at aol.com
Sun Jun 15 20:41:53 CEST 2008


On Jun 15, 12:10 pm, "ram.rac... at gmail.com" <ram.rac... at gmail.com>
wrote:
> On Jun 15, 7:43 pm, Peter Otten <__pete... at web.de> wrote:
>
> > ram.rac... at gmail.com wrote:
> > > On Jun 15, 6:58 pm, Christian Meesters <meest... at uni-mainz.de> wrote:
> > >> > I do need speed. Is there an option?
>
> > >> Mind telling us what you *actually* want to achieve? (What do you want to
> > >> calculate?)
>
> > >> Christian
>
> > > Physical simulations of objects with near-lightspeed velocity.
>
> > How did you determine that standard python floats are not good enough?
>
> I have a physical system set up in which a body is supposed to
> accelerate and to get very close to lightspeed, while never really
> attaining it. After approx. 680 seconds, Python gets stuck and tells
> me the object has passed lightspeed. I put the same equations in
> Mathematica, again I get the same mistake around 680 seconds. So I
> think, I have a problem with my model! Then I pump up the
> WorkingPrecision in Mathematica to about 10. I run the same equations
> again, and it works! At least for the first 10,000 seconds, the object
> does not pass lightspeed.
> I concluded that I need Python to work at a higher precision.
>
> > Everything beyond that is unlikely to be supported by the hardware and will
> > therefore introduce a speed penalty.
>
> I have thought of that as well. However I have no choice. I must do
> these calculations. If you know of any way that is supported by the
> hardware, it will be terrific, but for now the slower things will have
> to do.
>
> > Did you try gmpy?
>
> Not yet: I was kind of set back when I saw their homepage was last
> updated 2002.

Try looking here:

http://code.google.com/p/gmpy/

The developers have abandoned SourceForge.

> But I'll give it a try. You think it's the best thing
> there is?

I haven't tried everything, but it's very good.
You might also want to go to the GMP site itself
and get their manual. Likee anything else, your
results will be no better than your algorithms.

>
> Thanks,
> Ram.




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