On Jun 16, 12:57 am, "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> wrote: > On Jun 15, 11:30 pm, Christian Heimes <[EMAIL PROTECTED]> wrote: > > > > > [EMAIL PROTECTED] wrote: > > > 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. > > > I conclude that your algorithm is numerical wrong. It probably suffers > > from a rounding error which increases itself in every iteration. > > Increasing the precision doesn't solve your problem. It's only going to > > hide the fact that your algorithm doesn't do its job. > > > Please don't get me wrong. I don't want to imply that you are an idiot > > who doesn't know what he is doing. :] Most likely you weren't taught how > > to write numerical sound algorithms. Let's all blame your school or > > university. *g* > > > Numerics is a complex area and it took me more than a year to learn the > > basics. Don't be embarrassed! > > I'll try to read some. But I used mpmath to pump up the precision in > my code, and now the problem doesn't happen. So I think it's okay for > now.
Thanks to all contributors for your advice. Ram Rachum. -- http://mail.python.org/mailman/listinfo/python-list
