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sparse_vector_triangular_solve_dense_double(_:_:_:_:_:)

Solves the system of equations x = alpha * T⁻¹ * x for x where x is a dense vector and T is a triangular sparse matrix, with all operands containing double-precision values.

Declaration

func sparse_vector_triangular_solve_dense_double(_ transt: CBLAS_TRANSPOSE, _ alpha: Double, _ T: sparse_matrix_double!, _ x: UnsafeMutablePointer<Double>!, _ incx: sparse_stride) -> sparse_status

Parameters

  • transt:

    Specifies whether to perform the operation with T or the transpose of T. Must be one of CblasNoTrans or CblasTrans.

  • alpha:

    Scalar multiplier of T.

  • T:

    The sparse triangular matrix. Must be upper or lower triangular matrix. Will return Sparse_illegal_parameter if not a triangular matrix.

  • x:

    Pointer to the dense vector x. The dimension must match the dimension of the triangular matrix T. Behavior undefined if this is not met. Negative strides are supported. Note, unlike dense BLAS routines, the pointer points to the last element when stride is negative. On exit holds the solution to the system of equations.

  • incx:

    Increment between valid values in the dense vector x. Negative strides are supported.

Return Value

On success, SPARSE_SUCCESS (x will be updated with result of the operation). Will return SPARSE_ILLEGAL_PARAMETER if transt is invalid or if the matrix T is not triangular and x will be unchanged.

Discussion

See Also

Matrix-Vector Operations