naginterfaces.library.sparse.direct_real_gen_matmul¶
- naginterfaces.library.sparse.direct_real_gen_matmul(trans, alpha, icolzp, irowix, a, b, beta, c=None)[source]¶
direct_real_gen_matmul
computes a matrix-matrix or transposed matrix-matrix product involving a real, square, sparse nonsymmetric matrix stored in compressed column (Harwell–Boeing) format.For full information please refer to the NAG Library document for f11mk
https://support.nag.com/numeric/nl/nagdoc_30.2/flhtml/f11/f11mkf.html
- Parameters
- transstr, length 1
Specifies whether or not the matrix is transposed.
is computed.
is computed.
- alphafloat
, the scalar factor in the matrix multiplication.
- icolzpint, array-like, shape
The new column index array of sparse matrix . See the F11 Introduction.
- irowixint, array-like, shape
The row index array of sparse matrix . See the F11 Introduction.
- afloat, array-like, shape
The array of nonzero values in the sparse matrix .
- bfloat, array-like, shape
The matrix .
- betafloat
The scalar factor .
- cNone or float, array-like, shape , optional
The matrix .
- Returns
- cfloat, ndarray, shape
is overwritten by or depending on the value of .
- Raises
- NagValueError
- (errno )
On entry, .
Constraint: .
- (errno )
On entry, .
Constraint: .
- (errno )
On entry, .
Constraint: or .
- Notes
direct_real_gen_matmul
computes either the matrix-matrix product , or the transposed matrix-matrix product , according to the value of the argument , where is a real sparse nonsymmetric matrix, of arbitrary sparsity pattern with nonzero elements, and are real dense matrices. The matrix is stored in compressed column (Harwell–Boeing) storage format. The array stores all nonzero elements of , while arrays and store the compressed column indices and row indices of respectively.