On 20 August 2013 13:49, Vick <vick1...@orange.mu> wrote: > > From: Oscar Benjamin [mailto:oscar.j.benja...@gmail.com] > >> Well just send me some tutorial on how to build and obtain the >> coefficients for the butcher tableau for the RK4 as an example, and >> after I've mastered it, I'd give the dopri8 a shot. > > I am up for it so I'll see if I can find time to write a script that shows > how to do it. > > [Vick] Hope you've had the time to code it. I'm waiting for it.
Sorry, I haven't found the time yet. It is still on my todo list though! > By the way your code for the Adams-Moulton coefficients are actually the > Adams-Bashforth ones and so I copied it and modified the copy to have the > Adams-Moulton coefficients as well. This means that I have now an nth-order > predictor-corrector method to solve for ODEs. Oh sorry. That'll be a cut and paste error. My code lives in a private software library that I keep meaning to release on PyPI but it's not ready for public consumption in quite a number of ways. I'm glad that you worked it out though. You''ll probably understand what I mean now when I say that the AM or AB integrators need a secondary algorithm to bootstrap. The accuracy of the subsequent AM/AB method depends on the accuracy of that step. In the worst case you can just use rk4 with a very small time-step for this bit though. Oscar _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
