hipblassgeqrfstridedbatched Interface Reference

hipblassgeqrfstridedbatched Interface Reference#

HIPFORT API Reference: hipfort_hipblas::hipblassgeqrfstridedbatched Interface Reference

SOLVER API. More...

Public Member Functions
integer(kind(hipblas_status_success)) function	hipblassgeqrfstridedbatched_ (handle, m, n, a, lda, stridea, ipiv, stridep, myinfo, batchcount)

integer(kind(hipblas_status_success)) function	hipblassgeqrfstridedbatched_rank_0 (handle, m, n, a, lda, stridea, ipiv, stridep, myinfo, batchcount)

integer(kind(hipblas_status_success)) function	hipblassgeqrfstridedbatched_rank_1 (handle, m, n, a, lda, stridea, ipiv, stridep, myinfo, batchcount)

integer(kind(hipblas_status_success)) function	hipblassgeqrfstridedbatched_full_rank (handle, m, n, a, lda, stridea, ipiv, stridep, myinfo, batchcount)

Detailed Description

SOLVER API.

The geqrfStridedBatched functions compute the QR factorization of a batch of general m-by-n matrices.

The factorization of matrix \(A_i\) in the batch has the form:

\[ A_i = Q_i\left[\begin{array}{c} R_i\\% 0 \end{array}\right] \]

where \(R_i\) is upper triangular (upper trapezoidal if m < n), and \(Q_i\) is an m -by-m orthogonal/unitary matrix represented as the product of Householder matrices:

\[ Q_i = H_{i_1}H_{i_2}\cdots H_{i_k}, \quad \text{with} \: k = \text{min}(m,n) \]

Each Householder matrix \(H_{i_j}\) is given by:

\[ H_{i_j} = I - \text{ipiv}_j[j] \cdot v_{i_j} v_{i_j}' \]

where the first j -1 elements of Householder vector \(v_{i_j}\) are zero, and \(v_{i_j}[j] = 1\).

Supported precisions in rocSOLVER : s, d, c, and z.
Supported precisions in cuBLAS : No support.

Parameters

[in]	handle	- hipblasHandle_t.
[in]	m	- int. m >= 0. The number of rows of all the matrices A_i in the batch.
[in]	n	- int. n >= 0. The number of columns of all the matrices A_i in the batch.
[in,out]	A	- pointer to type. Array on the GPU (the size depends on the value of strideA). On entry, the m-by-n matrices A_i to be factored. On exit, the elements on and above the diagonal contain the factor R_i. The elements below the diagonal are the last m - j elements of Householder vector v_(i_j).
[in]	lda	- int. lda >= m. Specifies the leading dimension of matrices A_i.
[in]	strideA	- hipblasStride. Stride from the start of one matrix A_i to the next one A_(i+1). There is no restriction for the value of strideA. Normal use case is strideA >= lda*n.
[out]	ipiv	- pointer to type. Array on the GPU (the size depends on the value of strideP). Contains the vectors ipiv_i of corresponding Householder scalars.
[in]	strideP	- hipblasStride. Stride from the start of one vector ipiv_i to the next one ipiv_(i+1). There is no restriction for the value of strideP. Normal use is strideP >= min(m,n).
[out]	myInfo	- pointer to a int on the host. If info = 0, successful exit. If info = j < 0, the argument at position -j is invalid.
[in]	batchCount	- int. batchCount >= 0. Number of matrices in the batch.

Member Function/Subroutine Documentation