Zslu class

Wrapper class for a generic sparse direct solver. More...

Files
file	zslu.h
	Class Zslu: Wrapper class for a generic sparse direct solver.
Classes
struct	sZslu
	Contains public data members for Zslu class. More...
Typedefs
typedef struct sZslu	Zslu
	Declaration of the Zslu class as the Zslu structure.
Functions
Zslu *	Zslu_ctor (Vmem *vmem, int skey, int m, int n, int nnz, int *ia, int *ja, double *a)
	The Zslu constructor.
void	Zslu_dtor (Zslu **thee)
	The Zslu destructor.
int	Zslu_factor (Zslu *thee)
	Sparse LU factor the system.
int	Zslu_solve (Zslu *thee, int key, double *b, double *x)
	Use sparse LU factors to back/forward solve a linear system.
void	Zslu_memChk (Zslu *thee)
	Print the exact current malloc usage.
double	Zslu_lnDet (Zslu *thee)
	Calculate the log of the determinant of a SuperLU matrix.

---

Detailed Description

Wrapper class for a generic sparse direct solver.

---

Typedef Documentation

typedef struct sZslu Zslu

Declaration of the Zslu class as the Zslu structure.

Author:

Michael Holst

Returns:

None

---

Function Documentation

Zslu* Zslu_ctor	(	Vmem *	vmem,
		int	skey,
		int	m,
		int	n,
		int	nnz,
		int *	ia,
		int *	ja,
		double *	a
	)

The Zslu constructor.

Author:

Michael Holst

Note:

Class Zslu: Non-inlineable methods (zslu.c)

Returns:

Pointer to a newly allocated (empty) Zslu class

Parameters:

	vmem	Memory management object
	skey	index for storage format (0=row-wise YSMP, 1=col-wise YSMP)
	m	number of rows
	n	number of cols
	nnz	number of nonzeros
	ia	row-start (skey=0) or col-start (skey=1) in < j a >& < a >
	ja	col indices (skey=0) or row-indices (skey=1) for < a >
	a	the nonzeros in the matrix

void Zslu_dtor

(

Zslu **

thee

)

The Zslu destructor.

Author:

Michael Holst

Note:

Class Zslu: Non-inlineable methods (zslu.c)

Returns:

None

Parameters:

thee

Pointer to Zslu class

int Zslu_factor

(

Zslu *

thee

)

Sparse LU factor the system.

Author:

Michael Holst

Note:

Class Zslu: Non-inlineable methods (zslu.c)

Returns:

Success enumeration

Parameters:

thee

Pointer to Zslu class

double Zslu_lnDet

(

Zslu *

thee

)

Calculate the log of the determinant of a SuperLU matrix.

Author:

Nathan Baker (some restructuring by Michael Holst)

Note:

Class Zslu: Non-inlineable methods (zslu.c)
Uses SLU factorization and will be very slow for large matrices.
According to Sherry Li, author of SuperLU:
The diagonal blocks of both L and U are stored in the L matrix, which is returned from dgstrf(). The L matrix is a supernodal matrix, its structure is called SCformat in supermatrix.h. This is also illustrated by a small 5x5 example in Section 2.3 of the Users' Guide, see Figures 2.1 and 2.3. This example is in the code EXAMPLE/superlu.c. Since L is unit-diagonal, so the ones are not stored. Instead, the diagonal stored in L is really the diagonal for U. Therefore, you only need to extract those diagonal elements. One routine that you can hack to get the diagonal is dPrint_SuperNode_Matrix() in dutil.c. Another tricky part is the sign of the determinant. Since I am doing the following factorization Pr*A*Pc = LU, i.e., both row and column permutations may be applied, they are called perm_r and perm_c in the code. Their determinants will be 1 or -1, but you need to find out the sign by going through these permutations.

Returns:

the log of the determinant of a SuperLU matrix

Parameters:

thee

Pointer to Zslu class

void Zslu_memChk

(

Zslu *

thee

)

Print the exact current malloc usage.

Author:

Michael Holst

Note:

Class Zslu: Non-inlineable methods (zslu.c)

Returns:

None

Parameters:

thee

Pointer to Zslu class

int Zslu_solve	(	Zslu *	thee,
		int	key,
		double *	b,
		double *	x
	)

Use sparse LU factors to back/forward solve a linear system.

Author:

Michael Holst

Note:

Class Zslu: Non-inlineable methods (zslu.c)

Returns:

Success enumeration

Parameters:

	thee	Pointer to Zslu class
	key	index for different solution methods
	b	Pointer to the array b
	x	Pointer to the array x