ExplEuler Class Reference

Explicit Euler time integration scheme. More...

#include <timestepper.hpp>

Inheritance diagram for ExplEuler:

Collaboration diagram for ExplEuler:

Public Member Functions
	ExplEuler (const Config &config, MasterEq *mastereq_, Output *output_, int ninit_local)
	Constructor for explicit Euler scheme.
	~ExplEuler ()
void	evolveFWD (const double tstart, const double tstop, Vec x)
	Evolves state forward using explicit Euler method.
void	evolveBWD (const double tstart, const double tstop, const Vec x_stop, Vec x_adj, Vec grad, bool compute_gradient)
	Evolves adjoint backward using explicit Euler method.
Public Member Functions inherited from TimeStepper
	TimeStepper ()
	TimeStepper (const Config &config, MasterEq *mastereq_, Output *output_, int ninit_local)
	Constructor for time stepper.
virtual	~TimeStepper ()
double	getLeakageIntegral ()
double	getWeightedCostIntegral ()
double	getEnergyIntegral ()
double	getDPDMIntegral ()
Vec	getReducedGradient ()
void	setWriteTrajectoryDataFiles (bool write)
void	setOptimTarget (OptimTarget *optim_target_)
Vec	getFinalState (size_t iinit_local)
	Retrieves the final state for a specific local initial condition.
virtual double	getMinTimestepSize () const
	Get the smallest timestep size used during timestepping.
virtual Vec	solveODE (int initid, int iinit_local, Vec rho_t0)
	Solves the ODE forward in time.
virtual void	solveAdjointODE (int iinit_local, Vec rho_t0_bar, double Jbar_leakage, double Jbar_weightedcost, double Jbar_dpdm, double Jbar_energy)
	Solves the adjoint ODE backward in time.
double	evalLeakage (const Vec x)
	Evaluates leakage into guard levels.
void	evalLeakage_diff (const Vec x, Vec xbar, double Jbar)
	Computes derivative of leakage term.
double	evalWeightedCost (double time, const Vec x)
	Evaluates the weighted cost function term.
void	evalWeightedCost_diff (double time, const Vec x, Vec xbar, double Jbar)
	Computes derivative of weighted cost function term.
double	evalDpDm (Vec x, Vec xm1, Vec xm2)
	Evaluates second-order derivative variation for the state.
void	evalDpDm_diff (int n, Vec xbar, double Jbar)
	Computes derivative of second-order derivative variation term.
double	evalEnergy (double time)
	Evaluates energy integral term.
void	evalEnergy_diff (double time, double Jbar, Vec redgrad)
	Computes derivative of energy integral.

Protected Attributes
Vec	stage
	Intermediate vector.
Protected Attributes inherited from TimeStepper
Vec	x
	Auxiliary vector for forward time stepping.
Vec	xadj
	Auxiliary vector needed for adjoint (backward) time stepping.
Vec	xprimal
	Auxiliary vector for backward time stepping.
std::vector< std::vector< Vec > >	trajectory_states
	Storage for primal states during forward evolution, one trajectory for each local initial condition..
std::vector< Vec >	final_states
	Storage for final states for each local initial condition. Always filled after solveODE.
std::vector< Vec >	dpdm_states
	Storage for states needed for second-order derivative penalty.
int	mpirank_world
	MPI rank in global communicator.
int	mpisize_petsc
	MPI size in Petsc communicator.
int	mpirank_petsc
	MPI rank in Petsc communicator.
PetscInt	localsize_u
	Size of local sub vector u or v in state x=[u,v].
PetscInt	ilow
	First index of the local sub vector u,v.
PetscInt	iupp
	Last index (+1) of the local sub vector u,v.
bool	eval_leakage
	Flag to compute leakage integral term.
bool	eval_energy
	Flag to compute energy integral term.
bool	eval_dpdm
	Flag to compute second-order derivative integral term.
bool	eval_weightedcost
	Flag to compute weighted cost integral term.
double	leakage_integral
	Sums the integral over leakage.
double	energy_integral
	Sums the energy term.
double	dpdm_integral
	Sums second-order derivative variation value.
double	weightedcost_integral
	Sums the integral over weighted cost function.
double	weightedcost_width
	Width parameter for weighted cost function.
int	ntime
	Number of time steps.
double	total_time
	Final evolution time.
double	dt
	Time step size.
bool	writeTrajectoryDataFiles
	Flag to determine whether or not trajectory data will be written to files during forward simulation *‍/.
Vec	redgrad
	Reduced gradient vector for optimization.
OptimTarget *	optim_target
	Pointer to optimization target specification.
Output *	output
	Pointer to output handler.
MasterEq *	mastereq
	Pointer to master equation solver.

Detailed Description

Explicit Euler time integration scheme.

First-order explicit time stepping method. Simple, requires small time steps for stability. Mainly used for testing and comparison purposes.

Constructor & Destructor Documentation

ExplEuler()

ExplEuler::ExplEuler	(	const Config &	config,
		MasterEq *	mastereq_,
		Output *	output_,
		int	ninit_local
	)

Constructor for explicit Euler scheme.

Parameters

config	Configuration parameters from input file
mastereq_	Pointer to master equation solver
output_	Pointer to output handler
ninit_local	Number of initial conditions local to this processor

~ExplEuler()

ExplEuler::~ExplEuler

(

)

Member Function Documentation

evolveBWD()

void ExplEuler::evolveBWD ( const double  tstart, const double  tstop, const Vec  x_stop, Vec  x_adj, Vec  grad, bool  compute_gradient  )

virtual

Evolves adjoint backward using explicit Euler method.

Parameters

tstart	Start time (backward evolution)
tstop	Stop time (backward evolution)
x_stop	State at stop time
x_adj	Adjoint state vector
grad	Gradient vector to update
compute_gradient	Flag to compute gradient

Reimplemented from TimeStepper.

evolveFWD()

void ExplEuler::evolveFWD ( const double  tstart, const double  tstop, Vec  x  )

virtual

Evolves state forward using explicit Euler method.

Parameters

tstart	Start time
tstop	Stop time
x	State vector to evolve

Implements TimeStepper.

Member Data Documentation

stage

Vec ExplEuler::stage

protected

Intermediate vector.

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The documentation for this class was generated from the following files:

• /home/runner/work/quandary/quandary/include/timestepper.hpp
• /home/runner/work/quandary/quandary/src/timestepper.cpp