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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 mps_fire::result.

9 {
10  double s0 = 0; // derivatives do't depend on absolute value of the integration variable
11  CartesianState k1 = step * deriv( s0, start);
12  CartesianState k2 = step * deriv( s0+step/2, start+k1/2);
13  CartesianState k3 = step * deriv( s0+step/2, start+k2/2);
14  CartesianState k4 = step * deriv( s0+step, start+k3);
15 /*
16  std::cout << "k1 = " << k1.position() << k1.momentum() << std::endl;
17  std::cout << "k2 = " << k2.position() << k2.momentum() << std::endl;
18  std::cout << "k3 = " << k3.position() << k3.momentum() << std::endl;
19  std::cout << "k4 = " << k4.position() << k4.momentum() << std::endl;
20 */
21  CartesianState result = start + k1/6 + k2/3 + k3/3 + k4/6;
22  return result;
23 }
step