A base class to be inherited by objects that define residuals. More...

#include <Residual.h>

Inheritance diagram for CppNoddy::Residual< _Type >:

Public Member Functions
	Residual (const unsigned &order)
	Constructor for a 'square' residual object that is, N residuals for N unknowns. More...

	Residual (const unsigned &order, const unsigned &nvars)
	Constructor for a 'non-square' residual object that is, there are less residual constraints than unknowns. More...

virtual	~Residual ()
	An empty destructor, virtual since we have virtual methods. More...

void	update (const DenseVector< _Type > &state)
	Update the Residual object for the current set of state variables. More...

const DenseVector< _Type > &	residual () const
	Return a handle to the residuals corresponding to the last update state. More...

const DenseMatrix< _Type > &	jacobian () const
	Retrun a handle to the Jacobian of the residual corresponding to the last update state. More...

_Type &	delta ()

const _Type &	delta () const

unsigned	get_order () const
	Get the order of the residual vector. More...

unsigned	get_number_of_vars () const
	Get the number of variables that this residual condition is defined for. More...

virtual void	residual_fn (const DenseVector< _Type > &state, DenseVector< _Type > &f) const
	A blank virtual residual function method. More...

Protected Member Functions
virtual void	jacobian (const DenseVector< _Type > &state, DenseMatrix< _Type > &jac) const
	Because the residual evaluation at the current state is assumed to have already been done by the 'update' method, this routine is protected. More...

Protected Attributes
DenseMatrix< _Type >	JAC_AT_LAST_STATE
	Jacobian for the last state vector. More...

DenseVector< _Type >	FN_AT_LAST_STATE
	Residual for the last state vector. More...

DenseVector< _Type >	LAST_STATE
	The last state vector. More...

_Type	DELTA
	A default step for FD computation of the Jacobian. More...

unsigned	ORDER_OF_SYSTEM
	The order of the system of equations. More...

unsigned	NUMBER_OF_VARS
	The number of elements in the state vector. More...

Detailed Description

template<typename _Type>
class CppNoddy::Residual< _Type >

A base class to be inherited by objects that define residuals.

Definition at line 15 of file Residual.h.

Constructor & Destructor Documentation

◆ Residual() [1/2]

template<typename _Type >

CppNoddy::Residual< _Type >::Residual ( const unsigned & order )

Constructor for a 'square' residual object that is, N residuals for N unknowns.

Parameters

order The order of the residual vector

Definition at line 9 of file Residual.cpp.

                                                 : DELTA(1.e-8) {
    // set the order of the vector system and initialise the member data
    ORDER_OF_SYSTEM = order;
    NUMBER_OF_VARS = order;
    LAST_STATE = DenseVector<_Type>(NUMBER_OF_VARS, 0.0);
    FN_AT_LAST_STATE = DenseVector<_Type>(ORDER_OF_SYSTEM, 0.0);
    JAC_AT_LAST_STATE = DenseMatrix<_Type>(ORDER_OF_SYSTEM, NUMBER_OF_VARS, 0.0);
#ifdef TIME
    // timer
    T_UPDATER = Timer("Updating of the residual object:");
#endif
  }

References CppNoddy::Residual< _Type >::FN_AT_LAST_STATE, CppNoddy::Residual< _Type >::JAC_AT_LAST_STATE, CppNoddy::Residual< _Type >::LAST_STATE, CppNoddy::Residual< _Type >::NUMBER_OF_VARS, and CppNoddy::Residual< _Type >::ORDER_OF_SYSTEM.

◆ Residual() [2/2]

template<typename _Type >

CppNoddy::Residual< _Type >::Residual	(	const unsigned &	order,
		const unsigned &	nvars
	)

Constructor for a 'non-square' residual object that is, there are less residual constraints than unknowns.

Parameters

order	The number of residuals
nvars	The number of unknowns/variables

Definition at line 23 of file Residual.cpp.

                                                                         : DELTA(1.e-8) {
    // stet the order of the vector system and initialise the member data
    ORDER_OF_SYSTEM = order;
    NUMBER_OF_VARS = nstate;
    LAST_STATE = DenseVector<_Type>(NUMBER_OF_VARS, 0.0);
    FN_AT_LAST_STATE = DenseVector<_Type>(ORDER_OF_SYSTEM, 0.0);
    JAC_AT_LAST_STATE = DenseMatrix<_Type>(ORDER_OF_SYSTEM, NUMBER_OF_VARS, 0.0);
#ifdef TIME
    // timer
    T_UPDATER = Timer("Updating of the residual object:");
#endif
  }

References CppNoddy::Residual< _Type >::ORDER_OF_SYSTEM.

◆ ~Residual()

template<typename _Type >

CppNoddy::Residual< _Type >::~Residual

virtual

An empty destructor, virtual since we have virtual methods.

Definition at line 37 of file Residual.cpp.

                             {
#ifdef TIME
    std::cout << "\n";
    T_UPDATER.stop();
    T_UPDATER.print();
#endif
  }

Member Function Documentation

◆ delta() [1/2]

template<typename _Type >

_Type & CppNoddy::Residual< _Type >::delta

inline

Returns: A handle to the step size used when finite-differencing the residual vector to obtain the Jacobian

Definition at line 133 of file Residual.h.

                                       {
    return DELTA;
  }

◆ delta() [2/2]

template<typename _Type >

const _Type & CppNoddy::Residual< _Type >::delta

inline

Returns: A handle to the step size used when finite-differencing the residual vector to obtain the Jacobian

Definition at line 138 of file Residual.h.

                                                   {
    return DELTA;
  }

◆ get_number_of_vars()

template<typename _Type >

unsigned CppNoddy::Residual< _Type >::get_number_of_vars

inline

Get the number of variables that this residual condition is defined for.

Returns: The number of variables for the residual

Definition at line 128 of file Residual.h.

                                                            {
    return NUMBER_OF_VARS;
  }

◆ get_order()

template<typename _Type >

unsigned CppNoddy::Residual< _Type >::get_order

inline

Get the order of the residual vector.

Returns: The order/length of the residual vector

Definition at line 123 of file Residual.h.

                                                   {
    return ORDER_OF_SYSTEM;
  }

◆ jacobian() [1/2]

template<typename _Type >

const DenseMatrix< _Type > & CppNoddy::Residual< _Type >::jacobian

inline

Retrun a handle to the Jacobian of the residual corresponding to the last update state.

Definition at line 118 of file Residual.h.

                                                                   {
    return JAC_AT_LAST_STATE;
  }

◆ jacobian() [2/2]

template<typename _Type >

void CppNoddy::Residual< _Type >::jacobian	(	const DenseVector< _Type > &	state,
		DenseMatrix< _Type > &	jac
	)		const

protectedvirtual

Because the residual evaluation at the current state is assumed to have already been done by the 'update' method, this routine is protected.

This default uses a finite-differenced Jacobian. You can overload this to provide an analytic Jacobian if you wish

Parameters

state	Dummy state vector ... this is only here to make overloading easier, the 'last_x' member data is assumed in the default FD method.
jac	The NxN matrix Jacobian where the equation_fn is a vector function of length N.

Definition at line 46 of file Residual.cpp.

                                                                                               {
    DenseVector<_Type> new_state(state);
    // evaluation of the function
    DenseVector<_Type> f_at_new_state(ORDER_OF_SYSTEM, 0.0);
    // default is to FD the Jacobian
    for(std::size_t i = 0; i < NUMBER_OF_VARS; ++i) {
      new_state[ i ] += DELTA;
      residual_fn(new_state, f_at_new_state);
      new_state[ i ] -= DELTA;
      jac.set_col(i, (f_at_new_state - FN_AT_LAST_STATE) / DELTA);
    }
  }

References CppNoddy::DenseMatrix< _Type >::set_col().

◆ residual()

template<typename _Type >

const DenseVector< _Type > & CppNoddy::Residual< _Type >::residual

inline

Return a handle to the residuals corresponding to the last update state.

Definition at line 113 of file Residual.h.

                                                                   {
    return FN_AT_LAST_STATE;
  }

◆ residual_fn()

template<typename _Type >

virtual void CppNoddy::Residual< _Type >::residual_fn	(	const DenseVector< _Type > &	state,
		DenseVector< _Type > &	f
	)		const

inlinevirtual

A blank virtual residual function method.

Parameters

state	The unknown variable.
f	The residual function f(x).

Definition at line 63 of file Residual.h.

                                                                                           {
      std::string problem;
      problem = "The Residual::residual_fn method has not been implemented.\n";
      problem += "You have to implement this method to define the residual.\n";
      throw ExceptionRuntime(problem);
    }

◆ update()

template<typename _Type >

void CppNoddy::Residual< _Type >::update ( const DenseVector< _Type > & state )

inline

Update the Residual object for the current set of state variables.

Parameters

state The state at which to set the residual object

Definition at line 100 of file Residual.h.

                                                                 {
#ifdef TIME
    T_UPDATER.start();
#endif
    LAST_STATE = x;
    residual_fn(LAST_STATE, FN_AT_LAST_STATE);
    jacobian(LAST_STATE, JAC_AT_LAST_STATE);
#ifdef TIME
    T_UPDATER.stop();
#endif
  }

Referenced by CppNoddy::Equation_1matrix< _Type, _Xtype >::Equation_1matrix(), and CppNoddy::Residual< _Type >::Residual().

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

include/Residual.h
src/Residual.cpp

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ Residual() [1/2]

◆ Residual() [2/2]

◆ ~Residual()

Member Function Documentation

◆ delta() [1/2]

◆ delta() [2/2]

◆ get_number_of_vars()

◆ get_order()

◆ jacobian() [1/2]

◆ jacobian() [2/2]

◆ residual()

◆ residual_fn()

◆ update()

Member Data Documentation

◆ DELTA

◆ FN_AT_LAST_STATE

◆ JAC_AT_LAST_STATE

◆ LAST_STATE

◆ NUMBER_OF_VARS

◆ ORDER_OF_SYSTEM