cs_saddle_system.c File Reference

Set of functions to manipulate saddle-point systems defined by blocks relying on the cs_cdo_system_t structures: matrix/vector multiplications. More...

#include "cs_defs.h"
#include <assert.h>
#include "bft_error.h"
#include "bft_mem.h"
#include "cs_array.h"
#include "cs_math.h"
#include "cs_saddle_system.h"

Include dependency graph for cs_saddle_system.c:

Functions
cs_real_t *	cs_saddle_system_b11_inv_diag (cs_lnum_t b11_max_size, cs_cdo_system_helper_t *sh)
	Retrieve the inverse of the diagonal of the (1,1)-block matrix The storage of a matrix is in a gather view and the resulting array is in a scatter view. More...
void	cs_saddle_system_b11_matvec (const cs_cdo_system_helper_t *sh, cs_real_t *vec, cs_real_t *matvec)
	Perform a matrix-vector multiplication for the (1,1) block when the input vector is in a scatter state. More...
void	cs_saddle_system_b12_matvec (const cs_cdo_system_helper_t *sh, const cs_real_t *x2, cs_real_t *res, bool reset_res)
	Compute the resulting vector of the operation m12*x2 The block (1,2) is stored in an unassembled way and corresponds to the (2,1) block. Thus, one considers a transposition of this block. x2 corresponds to a "scatter" view. More...
void	cs_saddle_system_b21_matvec (const cs_cdo_system_helper_t *sh, const cs_real_t *x1, cs_real_t *res)
	Compute the resulting vector of the operation m21*x1 The block (2,1) is stored in an unassembled way. x1 corresponds to a "scatter" view. More...
void	cs_saddle_system_matvec (const cs_cdo_system_helper_t *sh, cs_real_t *x1, cs_real_t *x2, cs_real_t *r1, cs_real_t *r2)
	Compute the matrix-vector operation for a saddle-point system r1 = M11.x1 + M12.x2 (result for the first set) r2 = M21.x1 (result for the second set) More...
void	cs_saddle_system_residual (const cs_cdo_system_helper_t *sh, cs_real_t *x1, cs_real_t *x2, cs_real_t *res1, cs_real_t *res2)
	Compute the residual of the saddle-point system res1 = rhs1 - M11.x1 - M12.x2 (residual for the first set) res2 = rhs2 - M21.x1 (residual for the second set) More...

Detailed Description

Set of functions to manipulate saddle-point systems defined by blocks relying on the cs_cdo_system_t structures: matrix/vector multiplications.

Function Documentation

cs_saddle_system_b11_inv_diag()

cs_real_t* cs_saddle_system_b11_inv_diag	(	cs_lnum_t	b11_max_size,
		cs_cdo_system_helper_t *	sh
	)

Retrieve the inverse of the diagonal of the (1,1)-block matrix The storage of a matrix is in a gather view and the resulting array is in a scatter view.

Parameters

[in]	b11_max_size	max size related to the (1,1) block
[in]	sh	pointer to a system helper structure

Returns

a pointer to the computed array (scatter view)

cs_saddle_system_b11_matvec()

void cs_saddle_system_b11_matvec	(	const cs_cdo_system_helper_t *	sh,
		cs_real_t *	vec,
		cs_real_t *	matvec
	)

Perform a matrix-vector multiplication for the (1,1) block when the input vector is in a scatter state.

Thus, one performs a scatter --> gather (before the multiplication) and a gather --> scatter operation after the multiplication. One assumes that m11x1 is allocated to the right size. No check is done.

Parameters

[in]	sh	pointer to a system helper structure
[in,out]	vec	vector
[in,out]	matvec	resulting vector for the matrix-vector product

cs_saddle_system_b12_matvec()

void cs_saddle_system_b12_matvec	(	const cs_cdo_system_helper_t *	sh,
		const cs_real_t *	x2,
		cs_real_t *	res,
		bool	reset_res
	)

Compute the resulting vector of the operation m12*x2 The block (1,2) is stored in an unassembled way and corresponds to the (2,1) block. Thus, one considers a transposition of this block. x2 corresponds to a "scatter" view.

Parameters

[in]	sh	pointer to a system helper structure
[in]	x2	array to be multiplied
[in,out]	res	result array storing the matrix.vector operation
[in]	reset_res	false --> this is an update

cs_saddle_system_b21_matvec()

void cs_saddle_system_b21_matvec	(	const cs_cdo_system_helper_t *	sh,
		const cs_real_t *	x1,
		cs_real_t *	res
	)

Compute the resulting vector of the operation m21*x1 The block (2,1) is stored in an unassembled way. x1 corresponds to a "scatter" view.

Parameters

[in]	sh	pointer to a system helper structure
[in]	x1	array to be multiplied
[in,out]	res	result array storing the matrix.vector operation

cs_saddle_system_matvec()

void cs_saddle_system_matvec	(	const cs_cdo_system_helper_t *	sh,
		cs_real_t *	x1,
		cs_real_t *	x2,
		cs_real_t *	r1,
		cs_real_t *	r2
	)

Compute the matrix-vector operation for a saddle-point system r1 = M11.x1 + M12.x2 (result for the first set) r2 = M21.x1 (result for the second set)

Parameters

[in]	sh	pointer to a system helper structure
[in,out]	x1	array for the first part
[in,out]	x2	array for the second part
[in,out]	r1	result array for the first set of DoFs
[in,out]	r2	result array for the second set of DoFs

cs_saddle_system_residual()

void cs_saddle_system_residual	(	const cs_cdo_system_helper_t *	sh,
		cs_real_t *	x1,
		cs_real_t *	x2,
		cs_real_t *	res1,
		cs_real_t *	res2
	)

Compute the residual of the saddle-point system res1 = rhs1 - M11.x1 - M12.x2 (residual for the first set) res2 = rhs2 - M21.x1 (residual for the second set)

Parameters

[in]	sh	pointer to a system helper structure
[in,out]	x1	array for the first part
[in,out]	x2	array for the second part
[in,out]	res1	resulting residual vector for the first set of DoFs
[in,out]	res2	resulting residual vector for the second set of DoFs