#include <local_system.hh>

Public Types
typedef arma::Col< LongIdx >	DofVec

Public Member Functions
	LocalSystem ()
	Default constructor. More...

	LocalSystem (unsigned int nrows, unsigned int ncols)
	Constructor. More...

void	reset ()
	Resets the matrix, RHS, dofs to zero and clears solution settings. More...

void	reset (arma::uword nrows, arma::uword ncols)
	Resize and reset. More...

void	reset (const DofVec &row_dofs, const DofVec &col_dofs)

const arma::mat &	get_matrix ()

const arma::vec &	get_rhs ()

void	set_solution (unsigned int loc_dof, double solution, double diag=0.0)
	Set the position and value of known solution. E.g. Dirichlet boundary condition. More...

void	set_solution_row (uint loc_row, double solution, double diag=0.0)

void	set_solution_col (uint loc_col, double solution)

void	eliminate_solution ()

void	add_value (unsigned int row, unsigned int col, double mat_val, double rhs_val)
	Adds a single entry into the local system. More...

void	add_value (unsigned int row, unsigned int col, double mat_val)
	Matrix entry. Adds a single entry into the local system matrix. More...

void	add_value (unsigned int row, double rhs_val)
	RHS entry. Adds a single entry into the local system RHS. More...

void	set_matrix (arma::mat matrix)

void	set_rhs (arma::vec rhs)

void	set_sparsity (const arma::umat &sp)
	Sets the sparsity pattern for the local system. More...

Public Attributes
DofVec	row_dofs

DofVec	col_dofs

Protected Member Functions
void	set_size (unsigned int nrows, unsigned int ncols)

Protected Attributes
arma::mat	matrix
	local system matrix More...

arma::vec	rhs
	local system RHS More...

arma::mat	sparsity
	sparsity pattern More...

unsigned int	n_elim_rows

unsigned int	n_elim_cols

DofVec	elim_rows

DofVec	elim_cols

arma::vec	solution_rows

arma::vec	solution_cols

arma::vec	diag_rows

Static Protected Attributes
static constexpr double	almost_zero = std::numeric_limits<double>::min()

Friends
class	LinSys
	vector of global row indices where the solution is set (dirichlet BC) More...

Detailed Description

Local system class is meant to be used for local assembly and then pass to global linear system. The key idea is to take care of known solution values (Dirichlet boundary conditions) in a common way.

Usage of the class consists of 3 steps: 1) create local system, set global DoFs. 2) set all known values (Dirichlet BC) 3) set matrix and RHS entries (if the entry is on dirichlet row or column, it is now taken care of) 4) eliminate known solution and possibly fix the diagonal entries of the local system, where Dirichlet BC is set

TODO:

set dofs as references
use arma::vec<int> to keep dofs (efficient, can be constructed from raw arrays)
use local dof indeces to set solution
rename set_solution to set_constraint

Definition at line 27 of file local_system.hh.

Member Typedef Documentation

typedef arma::Col<LongIdx> LocalSystem::DofVec

Definition at line 30 of file local_system.hh.

Constructor & Destructor Documentation

LocalSystem::LocalSystem ( )

Default constructor.

Object must be initialized by subsequent call of reset(nrows, ncols).

Definition at line 8 of file local_system.cc.

LocalSystem::LocalSystem	(	unsigned int	nrows,
		unsigned int	ncols
	)

Constructor.

nrows is number of rows of local system ncols is number of columns of local system

Definition at line 12 of file local_system.cc.

Member Function Documentation

void LocalSystem::add_value	(	unsigned int	row,
		unsigned int	col,
		double	mat_val,
		double	rhs_val
	)

Adds a single entry into the local system.

row is local row index of local system col is local column index of local system mat_val is matrix entry value rhs_val is RHS entry value

Definition at line 176 of file local_system.cc.

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void LocalSystem::add_value	(	unsigned int	row,
		unsigned int	col,
		double	mat_val
	)

Matrix entry. Adds a single entry into the local system matrix.

row is local row index of local system col is local column index of local system mat_val is matrix entry value

Definition at line 186 of file local_system.cc.

void LocalSystem::add_value	(	unsigned int	row,
		double	rhs_val
	)

RHS entry. Adds a single entry into the local system RHS.

row is local row index of local system rhs_val is RHS entry value

Definition at line 195 of file local_system.cc.

void LocalSystem::eliminate_solution ( )

When finished with assembly of the local system, this function eliminates all the known dofs.

It is skipped if there is not any solution dof set.

During elimination, the (global) diagonal entries on the rows, where the solution is set, might be zero. Therefore it is necessary to set a proper value to the diagonal entry and respective RHS entry, such that the given solution holds. If preferred diagonal value has been set by set_solution then it is used.

Calling this function after the assembly of local system is finished is users's responsibility.

Definition at line 109 of file local_system.cc.

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const arma::mat& LocalSystem::get_matrix ( )

inline

Definition at line 65 of file local_system.hh.

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const arma::vec& LocalSystem::get_rhs ( )

inline

Definition at line 66 of file local_system.hh.

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void LocalSystem::reset ( )

Resets the matrix, RHS, dofs to zero and clears solution settings.

Definition at line 43 of file local_system.cc.

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void LocalSystem::reset	(	arma::uword	nrows,
		arma::uword	ncols
	)

Resize and reset.

Definition at line 53 of file local_system.cc.

void LocalSystem::reset	(	const DofVec &	row_dofs,
		const DofVec &	col_dofs
	)

Resize and reset. Set dofs vectors to reuse arrays provided by given vectors. Given vectors can not be changed until next call to of any reset function.

Definition at line 66 of file local_system.cc.

void LocalSystem::set_matrix ( arma::mat matrix )

Definition at line 203 of file local_system.cc.

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void LocalSystem::set_rhs ( arma::vec rhs )

Definition at line 209 of file local_system.cc.

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void LocalSystem::set_size	(	unsigned int	nrows,
		unsigned int	ncols
	)

protected

Definition at line 27 of file local_system.cc.

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void LocalSystem::set_solution	(	unsigned int	loc_dof,
		double	solution,
		double	diag = `0.0`
	)

Set the position and value of known solution. E.g. Dirichlet boundary condition.

loc_dofs is local row index in solution vector solution is the values of the solution diag_val is preferred diagonal value on the solution row

Definition at line 76 of file local_system.cc.

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void LocalSystem::set_solution_col	(	uint	loc_col,
		double	solution
	)

Definition at line 91 of file local_system.cc.

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void LocalSystem::set_solution_row	(	uint	loc_row,
		double	solution,
		double	diag = `0.0`
	)

Definition at line 84 of file local_system.cc.

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void LocalSystem::set_sparsity ( const arma::umat & sp )

Sets the sparsity pattern for the local system.

Due to petsc options: MatSetOption(matrix_, MAT_IGNORE_ZERO_ENTRIES, PETSC_TRUE) all zeros will be thrown away from the system. If we do not want some zero entries in the system matrix to be thrown away, we can set these entries with this almost zero value.

Almost_zero values will be set in all entries: sp(i,j) != 0

Definition at line 214 of file local_system.cc.

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Friends And Related Function Documentation

friend class LinSys

friend

vector of global row indices where the solution is set (dirichlet BC)

vector of solution values at global_solution_rows indices (dirichlet BC) diagonal values for dirichlet BC rows (set in set_solution) Optimization. Is false if solution (at least one entry) is known.

Definition at line 180 of file local_system.hh.

Member Data Documentation

constexpr double LocalSystem::almost_zero = std::numeric_limits<double>::min()

staticprotected

Due to petsc options: MatSetOption(matrix_, MAT_IGNORE_ZERO_ENTRIES, PETSC_TRUE) all zeros will be thrown away from the system. If we do not want some zero entries in the system matrix to be thrown away, we can set these entries with this almost zero value.

This is done for example when BC values are eliminated and later the BC changes to different type (e.g. seepage). Another case is keeping the structure of matrix unchanged for the schur complements - for that we fill the whole diagonal (escpecially block C in darcy flow) with artificial zeros.

Definition at line 164 of file local_system.hh.

DofVec LocalSystem::col_dofs

Definition at line 37 of file local_system.hh.

arma::vec LocalSystem::diag_rows

protected

Definition at line 154 of file local_system.hh.

DofVec LocalSystem::elim_cols

protected

Definition at line 151 of file local_system.hh.

DofVec LocalSystem::elim_rows

protected

Definition at line 150 of file local_system.hh.

arma::mat LocalSystem::matrix

protected

local system matrix

Definition at line 144 of file local_system.hh.

unsigned int LocalSystem::n_elim_cols

protected

Definition at line 149 of file local_system.hh.

unsigned int LocalSystem::n_elim_rows

protected

Definition at line 149 of file local_system.hh.

arma::vec LocalSystem::rhs

protected

local system RHS

Definition at line 145 of file local_system.hh.

DofVec LocalSystem::row_dofs

Global row and col indices. Are public and can be freely set. Nevertheless one can also provide reference to already existing arrays through specific constructor or reset function.

Definition at line 37 of file local_system.hh.

arma::vec LocalSystem::solution_cols

protected

Definition at line 153 of file local_system.hh.

arma::vec LocalSystem::solution_rows

protected

Definition at line 152 of file local_system.hh.

arma::mat LocalSystem::sparsity

protected

sparsity pattern

Definition at line 147 of file local_system.hh.

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

/opt/flow123d/flow123d/src/la/local_system.hh
/opt/flow123d/flow123d/src/la/local_system.cc

Public Types

Public Member Functions

Public Attributes

Protected Member Functions

Protected Attributes

Static Protected Attributes

Friends

Detailed Description

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

Member Data Documentation