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 6 of file RK4OneStep.cc.

References relval_steps::k2, and mps_fire::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;
}