lammps/lib/atc/TimeIntegrator.h

383 lines
11 KiB
C++

#ifndef TIME_INTEGRATOR_H
#define TIME_INTEGRATOR_H
#include "MatrixLibrary.h"
#include "TimeFilter.h"
#include "ATC_TypeDefs.h"
namespace ATC {
// forward declarations
class ATC_Method;
class ATC_Coupling;
class TimeIntegrationMethod;
/**
* @class AtomTimeIntegrator
* @brief Base class for various time integrators for atomic quantities (replacing other lammps fixes)
*/
class AtomTimeIntegrator {
public:
// constructor
AtomTimeIntegrator(){};
// destructor
virtual ~AtomTimeIntegrator(){};
/** create and get necessary transfer operators */
virtual void construct_transfers(){};
/** Predictor phase, Verlet first step for velocity */
virtual void init_integrate_velocity(double dt){};
/** Predictor phase, Verlet first step for position */
virtual void init_integrate_position(double dt){};
/** Corrector phase, Verlet second step for velocity */
virtual void final_integrate(double dt){};
};
/**
* @class AtomTimeIntegratorType
* @brief class for applying velocity-verlet based on atom type
*/
class AtomTimeIntegratorType : public AtomTimeIntegrator {
public:
// constructor
AtomTimeIntegratorType(ATC_Method * atc, AtomType atomType);
// destructor
virtual ~AtomTimeIntegratorType(){};
/** create and get necessary transfer operators */
virtual void construct_transfers();
/** Predictor phase, Verlet first step for velocity */
virtual void init_integrate_velocity(double dt);
/** Predictor phase, Verlet first step for position */
virtual void init_integrate_position(double dt);
/** Corrector phase, Verlet second step for velocity */
virtual void final_integrate(double dt);
protected:
/** pointer to atc object */
ATC_Method * atc_;
/** atom type this is applied to */
AtomType atomType_;
/** atomic masses */
DENS_MAN * mass_;
/** atomic positions */
DENS_MAN * position_;
/** atomic velocities */
DENS_MAN * velocity_;
/** atomic forces */
DENS_MAN * force_;
// workspace
DENS_MAT _deltaQuantity_;
private:
// DO NOT define this
AtomTimeIntegratorType();
};
/**
* @class TimeIntegrator
* @brief Base class for various time integrators for FE quantities
*/
class TimeIntegrator {
public:
/** types of time integration */
enum TimeIntegrationType {
NONE=0,
STEADY,
VERLET,
GEAR,
FRACTIONAL_STEP,
EXPLICIT,
IMPLICIT,
CRANK_NICOLSON,
DIRECT
};
// constructor
TimeIntegrator(ATC_Coupling * atc,
TimeIntegrationType timeIntegrationType = STEADY);
// destructor
virtual ~TimeIntegrator();
/** parser/modifier */
virtual bool modify(int narg, char **arg){return false;};
/** create objects to implement requested numerical method */
virtual void construct_methods() = 0;
/** create and get necessary transfer operators */
virtual void construct_transfers();
/** pre time integration initialization of data */
virtual void initialize();
/** flag if reset is needed */
bool need_reset() const {return needReset_;};
// time step methods, corresponding to ATC_Coupling
/** first part of pre_initial_integrate */
virtual void pre_initial_integrate1(double dt);
/** second part of pre_initial_integrate */
virtual void pre_initial_integrate2(double dt);
/** first part of post_initial_integrate */
virtual void post_initial_integrate1(double dt);
/** second part of post_initial_integrate */
virtual void post_initial_integrate2(double dt);
/** first part of pre_final_integrate */
virtual void pre_final_integrate1(double dt);
/** second part of pre_final_integrate */
virtual void pre_final_integrate2(double dt);
/** first part of post_final_integrate */
virtual void post_final_integrate1(double dt);
/** second part of post_final_integrate */
virtual void post_final_integrate2(double dt);
/** third part of post_final_integrate */
virtual void post_final_integrate3(double dt);
/** checks to see if first RHS computation is needed */
virtual bool has_final_predictor();
/** checks to see if second RHS computation is needed */
virtual bool has_final_corrector();
/** adds any contributions from time integrator to RHS */
virtual void add_to_rhs();
/** post processing step prior to output */
virtual void post_process();
/** add output data */
virtual void output(OUTPUT_LIST & outputData);
/** pack persistent fields */
virtual void pack_fields(RESTART_LIST & data);
/** finalize any data */
virtual void finish();
// Member data access
/** access to time integration type */
TimeIntegrationType time_integration_type() const
{ return timeIntegrationType_; };
/** access to ATC Transfer object */
ATC_Coupling * atc() {return atc_;};
/** access to time filter object */
TimeFilter * time_filter() {return timeFilter_;};
/** access to time filter manager object */
TimeFilterManager * time_filter_manager() {return timeFilterManager_;};
/** force the integrator to be reset */
void force_reset() {needReset_ = true;};
/** force the integrator not to be reset */
void force_no_reset() {needReset_ = false;};
protected:
/** pointer to time integrator method */
TimeIntegrationMethod * timeIntegrationMethod_;
/** pointer to access ATC methods */
ATC_Coupling * atc_;
/** time filter for specific updates */
TimeFilter * timeFilter_;
/** time filter manager for getting time filtering info */
TimeFilterManager * timeFilterManager_;
/** type of integration scheme being used */
TimeIntegrationType timeIntegrationType_;
/** flat to reset data */
bool needReset_;
private:
// DO NOT define this
TimeIntegrator();
};
/**
* @class TimeIntegrationMethod
* @brief Base class for time integration methods which update FE quantities
*/
class TimeIntegrationMethod {
public:
// constructor
TimeIntegrationMethod(TimeIntegrator * timeIntegrator);
// destructor
virtual ~TimeIntegrationMethod(){};
/** create and get necessary transfer operators */
virtual void construct_transfers(){};
/** pre time integration */
virtual void initialize(){};
// time step methods, corresponding to ATC_Coupling and TimeIntegrator
/** first part of pre_initial_integrate */
virtual void pre_initial_integrate1(double dt){};
/** second part of pre_initial_integrate */
virtual void pre_initial_integrate2(double dt){};
/** first part of post_initial_integrate */
virtual void post_initial_integrate1(double dt){};
/** second part of post_initial_integrate */
virtual void post_initial_integrate2(double dt){};
/** first part of pre_final_integrate */
virtual void pre_final_integrate1(double dt){};
/** second part of pre_final_integrate */
virtual void pre_final_integrate2(double dt){};
/** first part of post_final_integrate */
virtual void post_final_integrate1(double dt){};
/** second part of post_final_integrate */
virtual void post_final_integrate2(double dt){};
/** third part of post_final_integrate */
virtual void post_final_integrate3(double dt){};
/** checks to see if first RHS computation is needed */
virtual bool has_final_predictor() {return false;};
/** checks to see if second RHS computation is needed */
virtual bool has_final_corrector() {return false;};
/** adds any contributions from time integrator to RHS */
virtual void add_to_rhs() {};
/** post processing step */
virtual void post_process(){};
/** add output data */
virtual void output(OUTPUT_LIST & outputData){};
/** pack persistent fields */
virtual void pack_fields(RESTART_LIST & data){};
/** finalize any states */
virtual void finish(){};
protected:
/** owning time integrator */
TimeIntegrator * timeIntegrator_;
/** associated ATC transfer object */
ATC_Coupling * atc_;
private:
// DO NOT define this
TimeIntegrationMethod();
};
//--------------------------------------------------------
//--------------------------------------------------------
// time integration functions not associated
// with any particular class
//--------------------------------------------------------
//--------------------------------------------------------
inline void gear1_4_predict(MATRIX & f,
MATRIX & dot_f,
MATRIX & ddot_f,
const MATRIX & dddot_f,
double dt)
// 4th order Gear integrator for 1rst order ODE predictor step
{
f = f + dot_f*dt + ddot_f*(1./2.*dt*dt) + dddot_f*(1./6.*dt*dt*dt);
dot_f = dot_f + ddot_f*dt+dddot_f*(1./2.*dt*dt);
ddot_f = ddot_f + dddot_f*dt;
};
inline void gear1_3_predict(MATRIX & f,
MATRIX & dot_f,
const MATRIX & ddot_f,
double dt)
// 3rd order Gear integrator for 1rst order ODE predictor step
{
f = f + dot_f*dt + ddot_f*(1./2.*dt*dt);
dot_f = dot_f + ddot_f*dt;
};
inline void gear1_4_correct(MATRIX & f,
MATRIX & dot_f,
MATRIX & ddot_f,
MATRIX & dddot_f,
const MATRIX & R_f,
double dt)
// 4th order Gear integrator for 1rst order ODE corrector step
{
f = f + (3./8.)*R_f;
dot_f = dot_f + (1./dt)*R_f;
ddot_f = ddot_f + (3./2./dt/dt)*R_f;
dddot_f = dddot_f + (1./dt/dt/dt)*R_f;
};
inline void gear1_3_correct(MATRIX & f,
MATRIX & dot_f,
MATRIX & ddot_f,
const MATRIX & R_f,
double dt)
// 3rd order Gear integrator for 1rst order ODE corrector step
{
f = f + (5./12.)*R_f;
dot_f = dot_f + (1./dt)*R_f;
ddot_f = ddot_f + (1./dt/dt)*R_f;
};
inline void explicit_1(MATRIX & f,
const MATRIX & dot_f,
double dt)
// 1rst order explict ODE update
{
f = f + dt*dot_f;
};
inline void explicit_2(MATRIX & f,
const MATRIX & dot_f,
const MATRIX & ddot_f,
double dt)
// 2nd order explict ODE update
{
f = f + dt*dot_f + .5*dt*dt*ddot_f;
};
};
#endif