RK4OneStep Class Reference

#include <RK4OneStep.h>

Public Member Functions
CartesianState	operator() (const CartesianState &start, const RKCartesianDerivative &deriv, double step) const

Detailed Description

Definition at line 9 of file RK4OneStep.h.

Member Function Documentation

CartesianState RK4OneStep::operator()	(	const CartesianState &	start,
		const RKCartesianDerivative &	deriv,
		double	step
	)		const

Definition at line 7 of file RK4OneStep.cc.

References relval_steps::k2, and query::result.

{
  double s0 = 0; // derivatives do't depend on absolute value of the integration variable
  CartesianState k1 = step * deriv( s0, start);
  CartesianState k2 = step * deriv( s0+step/2, start+k1/2);
  CartesianState k3 = step * deriv( s0+step/2, start+k2/2);
  CartesianState k4 = step * deriv( s0+step, start+k3);
/*
  std::cout << "k1 = " << k1.position() << k1.momentum() << std::endl;
  std::cout << "k2 = " << k2.position() << k2.momentum() << std::endl;
  std::cout << "k3 = " << k3.position() << k3.momentum() << std::endl;
  std::cout << "k4 = " << k4.position() << k4.momentum() << std::endl;
*/
  CartesianState result = start + k1/6 + k2/3 + k3/3 + k4/6;
  return result;
}