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gradientFlow_RungeKutta_2nd.cpp
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1 
15 
16 const std::string GradientFlow_RungeKutta_2nd::class_name = "GradientFlow_RungeKutta_2nd";
17 
18 //====================================================================
19 void GradientFlow_RungeKutta_2nd::flow(double& t, double& Estep, Field_G& U)
20 {
21  //- aliases
22  Field_G& w0 = U;
23  Field_G& w2 = U;
24 
25  Field_G& w1 = m_w1;
26 
27  Field_G& z0 = m_z0;
28  Field_G& z1 = m_z1;
29 
30  //- step 0
31  // calculate gradient of m_action Z_0 (SA)
32  m_action->force(z0, w0);
33 
34  // W_1=e^{c2*Z_0}*U
35  mult_exp_Field_G(w1, 0.5 * Estep, z0, w0, m_Nprec);
36 
37  //- step 1
38  // Z_1
39  m_action->force(z1, w1);
40 
41  // V_out=e^{Z_1}*W_0
42  mult_exp_Field_G(w2, Estep, z1, w0, m_Nprec);
43 
44  t += Estep;
45 }
46 
47 
48 //====================================================================
49 //============================================================END=====
GradientFlow_RungeKutta_2nd::m_w1
Field_G m_w1
Definition: gradientFlow_RungeKutta_2nd.h:43
Action::force
virtual void force(Field &)=0
returns force for molcular dynamical update of conjugate momenta.
GradientFlow_RungeKutta_2nd::m_action
Action * m_action
Definition: gradientFlow_RungeKutta_2nd.h:38
GradientFlow_RungeKutta_2nd::flow
void flow(double &t, double &Estep, Field_G &U)
Definition: gradientFlow_RungeKutta_2nd.cpp:19
gradientFlow_RungeKutta_2nd.h
GradientFlow_RungeKutta_2nd::m_z1
Field_G m_z1
Definition: gradientFlow_RungeKutta_2nd.h:44
GradientFlow_RungeKutta_2nd::m_z0
Field_G m_z0
Definition: gradientFlow_RungeKutta_2nd.h:44
mult_exp_Field_G
void mult_exp_Field_G(Field_G &W, const double alpha, const Field_G &iP, const Field_G &U, const int Nprec)
Definition: field_G_imp.cpp:496
Field_G
SU(N) gauge field.
Definition: field_G.h:38
GradientFlow_RungeKutta_2nd::class_name
static const std::string class_name
Definition: gradientFlow_RungeKutta_2nd.h:32
GradientFlow_RungeKutta_2nd::m_Nprec
int m_Nprec
Definition: gradientFlow_RungeKutta_2nd.h:39