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Next: MLSOLV(3LAS) Up: Manual Pages Previous: ITERSOLV(3LAS)

MATRIX(3LAS)

NAME

M_Constr, M_Destr, M_SetName, M_GetName, M_GetRowDim, M_GetClmDim, M_GetElOrder, M_SetLen, M_GetLen, M_SetEntry, M_GetPos, M_GetVal, M_AddVal, M__SetEntry, M__GetPos, M__GetVal, M__AddVal, M_GetEl, M_SortEl, M_Lock, M_Unlock -- type Matrix for general rectangular sparse matrices

SYNOPSIS

#include <laspack/matrix.h>

typedef double Real; 

typedef enum {
    Rowws,
    Clmws
} ElOrderType; 

typedef enum {
    Normal,
    Tempor
} InstanceType; 

void M_Constr(Matrix *M, char *Name, size_t RowDim, size_t ClmDim,
              ElOrderType ElOrder, InstanceType Instance, Boolean OwnData);
void M_Destr(Matrix *M);
void M_SetName(Matrix *M, char *Name);
char *M_GetName(Matrix *M);
size_t M_GetRowDim(Matrix *M);
size_t M_GetClmDim(Matrix *M);
ElOrderType M_GetElOrder(Matrix *M);
void M_SetLen(Matrix *M, size_t RoC, size_t Len);
size_t M_GetLen(Matrix *M, size_t RoC);
void M_SetEntry(Matrix *M, size_t RoC, size_t Entry, size_t Pos, Real Val);
Real M_GetPos(Matrix *M, size_t RoC, size_t Entry);
size_t M_GetEVal(Matrix *M, size_t RoC, size_t Entry);
void M_AddVal(Matrix *M, size_t RoC, size_t Entry, Real Val);
void M__SetEntry(Matrix *M, size_t RoC, size_t Entry, size_t Pos, Real Val);
Real M__GetPos(Matrix *M, size_t RoC, size_t Entry);
size_t M__GetVal(Matrix *M, size_t RoC, size_t Entry);
void M__AddVal(Matrix *M, size_t RoC, size_t Entry, Real Val);
Real M_GetEl(Matrix *M, size_t Row, size_t Clm);
void M_SortEl(Matrix *M);
void M_Lock(Matrix *M);
void M_Unlock(Matrix *M);

DESCRIPTION

The procedure M_Constr is the constructor of the type Matrix. It creates and initializes a new variable of this type directed by the parameter M. As symbolic name, the string Name is used. The row and column dimensions of the matrix are defined by RowDim and ClmDim. The parameter ElOrder determines the order in which the matrix elements are stored. It can be set to Rowws and Clmws for row-wise and column-wise ordering, respectively. For matrices used in application codes, own should always use the parameters Instance = Normal and OwnData = True. In this case, M_Constr allocates memory for internal auxiliary variables needed for storage of matrix elements and initializes them. Other parameter combinations for Instance and OwnData are intended for internal usage by LASPack .

The procedure M_Destr is the destructor of type Matrix. It releases memory of matrix elements as well as internal auxiliary variables.

The procedure M_SetName resets the symbolic name of the matrix. This can be queried by the procedure M_GetName.

The procedures M_GetRowDim and M_GetClmDim return the row and column dimension of the matrix, respectively.

The procedure M_GetElOrder returns the element order of matrix elements.

The procedure M_SetLen sets or resets the length, i.e. the number of non-zero elements, of the row or column RoC (1 <= RoC <= RowDim / ClmDim) to Len, and allocates memory for element storage. The length of each row or column is initialized by zero. The current value can be queried by the procedure M_GetLen.

The procedure M_SetEntry assigns the position Pos and the value Val of a non-zero element in the row or column RoC to the entry Entry (0 <= Entry <= Len - 1).

The procedures M_GetPos and M_GetVal return the position and the value of the non-zero element stored as entry Entry in the row or column RoC, respectively.

The procedure M_AddEntry adds the value Val to the non-zero element stored as entry Entry in the row or column RoC.

The procedures M__GetLen, M__SetEntry, M__GetPos, M__GetVal and M__AddEntry have the same functionality as the routines M_GetLen, M_SetEntry, M_GetPos, M_GetVal and M_AddEntry. They are designed as preprocessing macros and are thus essentially faster. Because no range check is made they should not be used in the test phase of the application code.

The procedure M_GetEl returns the value of the matrix element in the row Row and column Clm. In contrast to other procedures, all matrix elements are considered here. If any element is not stored, zero is returned.

The procedure M_SortEl sorts elements of each row or column in ascending order.

In subroutines, the procedure M_Lock should be applied to all passed parameters of the type Matrix. This ensures that, if they are of temporary kind, they are not released within any LASPack routine before the procedure is leaved. This should be carried out by a call of M_Unlock which have to be called at the end of the procedure.

FILES

matrix.h ... header file
matrix.c ... source file

EXAMPLES

The matrix

    | 1  2  1  0  0  0  0 |
    | 0  0  1  2  1  0  0 |
    | 0  0  0  0  1  2  1 |

which may be used e.g. for weighted restriction of grid functions from a seven point to a three point grid, could be generated by the following code fragment:

Matrix R;
size_t Row;

...

M_Constr(&R, "R", 3, 7, Rowws, Normal, True);

for (Row = 1; Row <= 3; Row++) {
    M_SetLen(&R, Row, 3);
    M_SetEntry(&R, Row, 0, 2 * Row - 1, 0.5);      
    M_SetEntry(&R, Row, 1, 2 * Row,     1.0);      
    M_SetEntry(&R, Row, 2, 2 * Row + 1, 0.5);      
}

...

M_Destr(&R);