Methods for solving ordinary differential equations, the program and system

摘要

PROBLEM TO BE SOLVED: To reduce a computational complexity for simultaneous ordinary differential equations by a computer.;SOLUTION: This system calculates a difference ▵ between a calculation term of order N and a calculation term of order N+1, when solving an individual ordinary differential equation of the simultaneous ordinary differential equations, by an embedding type Runge-Kutta method such as a Runge-Kutta Vehrberg method, determines whether the difference is smaller than a prescribed threshold value ▵₀ or not, determines a step size according to a prescribed calculation expression determined by a ▵₀/▵, when the ▵≤▵₀, to be advanced to the next calculation, and issues a recalculation command to only a strand of calculating the ordinary differential equation generating an error brought into ▵▵₀. The step size determined by a ▵₀/▵ is set in the recalculation strand. The calculation of the whole of the simultaneous ordinary differential equations is progressed when the error gets smaller than the prescribed threshold value ▵₀ therefrom, by recalculation with an interpolation value, since a pace is matched with that of a strand for calculating the other ordinary differential equation not generating an error.;COPYRIGHT: (C)2011,JPO&INPIT