TransWikia.com

How is the final result calculated in RK-Dopri(4,5)?

Computational Science Asked on August 26, 2021

I have found a toy implementation of RK-Dopri(4,5), written in Python.

I am concerned however, about line 118:

y = y + h * (b1*K1+b3*K3+b4*K4+b5*K5+b6*K6)

Has the term b2*K2 been omitted on purpose? I have a feeling that it is not, given (1.8) in Hairer, Wanner and Norsett:

enter image description here

Can you confirm?

One Answer

$b_2$ is zero in the Butcher tableau for Dormand-Prince, so you can skip that term.

Note that also the code you linked to contains lines b2 = 0.0, b2p = 0.0, which are just there as a reminder because those variables are never used.

Correct answer by Federico Poloni on August 26, 2021

Add your own answers!

Ask a Question

Get help from others!

© 2024 TransWikia.com. All rights reserved. Sites we Love: PCI Database, UKBizDB, Menu Kuliner, Sharing RPP