hipblassgeqrfbatched Interface Reference

hipblassgeqrfbatched Interface Reference#

HIPFORT API Reference: hipfort_hipblas::hipblassgeqrfbatched Interface Reference

SOLVER API. More...

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

Detailed Description

SOLVER API.

The geqrfBatched function computes 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:

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

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 : s, d, c, and z.

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	- Array of pointers to type. Each pointer points to an array on the GPU of dimension lda*n. 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.
[out]	ipiv	- array of pointers to type. Each pointer points to an array on the GPU of dimension min(m, n). Contains the vectors ipiv_i of corresponding Householder scalars.
[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