scale_linear_system.c File Reference

#include "adh.h"

Functions
void	scale_linear_system (int *indptr_diag, int *cols_diag, double *vals_diag, int *indptr_off_diag, int *cols_off_diag, double *vals_off_diag, double *b, double *x, double *scale_vect, int local_size, int size, int rank, int *ghosts, int nghost)
	Scales a linear of systems based on max row entry, modifies matrix values and saves a scale_vect for later reverse scaling. More...
void	unscale_linear_system (double *x, double *x0, double *scale_vect, int local_size)
	Rescales solution after a linear solve of system that was scaled using scale_linear_system. More...

Detailed Description

This file has functions responsible for scaling the linear system in split CSR format based on max row entry

Function Documentation

scale_linear_system()

void scale_linear_system	(	int *	indptr_diag,
		int *	cols_diag,
		double *	vals_diag,
		int *	indptr_off_diag,
		int *	cols_off_diag,
		double *	vals_off_diag,
		double *	b,
		double *	x,
		double *	scale_vect,
		int	local_size,
		int	size,
		int	rank,
		int *	ghosts,
		int	nghost
	)

Scales a linear of systems based on max row entry, modifies matrix values and saves a scale_vect for later reverse scaling.

Author

Mark Loveland

Bug:

none

Warning

none

Copyright

AdH

Parameters

[in]	indptr_diag	(int*) - indeces of first/last index for each row in diagonal block (local to process) in split CSR matrix
[in]	cols_diag	(int*) - column numbers (local to process) of diagonal block in split CSR matrix
[in,out]	vals_diag	(double*) - array of doubles that are the nonzero entries of diagonal block (local to process) in split CSR matrix
[in]	indptr_off_diag	(int*) - indeces of first/last index for each row in off-diagonal block (local to process) in split CSR matrix
[in]	cols_off_diag	(int*) - column numbers (global) of off-diagonal block in split CSR matrix
[in,out]	vals_off_diag	(double*) - array of doubles that are the nonzero entries of off-diagonal block (local to process) in split CSR matrix
[in,out]	b	(double*) - scaled rhs of the linear system Ax=b
[in,out]	x	(double*) - scaled solution of the linear system Ax=b
[in]	scale_vect	(double*) - the vector that scaled the system of equations prior to solve, used for rescaling after solve is finished
[in]	local_size	(int) - number of equations (rows in the matrix) owned by the process
[in]	size	(int) - number of rows + number of ghost d.o.f.s present
[in]	rank	(int) - MPI rank
[in]	ghosts	(int*) - array of global dof numbers that are ghosts on the process
[in]	nghost	(int) - number of ghost d.o.f.s on the process

Returns

integer that is a code if the solve worked or not

Note

unscale_linear_system()

void unscale_linear_system	(	double *	x,
		double *	x0,
		double *	scale_vect,
		int	local_size
	)

Rescales solution after a linear solve of system that was scaled using scale_linear_system.

Author

Mark Loveland

Bug:

none

Warning

none

Copyright

AdH

Parameters

[in,out]	x	(double*) - solution vector that comes from solving the prescaled Ax=b system
[in]	x0	(double*) - the initial solution passed to iterative solver (after scaling)
[in]	scale_vect	(double*) - the vector that was used for scaling
[in]	local_size	(int) - number of d.o.f owned by process

Note

To be paired with a call to scale_linear_system BEFORE solve