rocsolver_cheevd_batched Interface Reference

rocsolver_cheevd_batched Interface Reference#

HIPFORT API Reference: hipfort_rocsolver::rocsolver_cheevd_batched Interface Reference

The HEEVD_BATCHED functions compute the eigenvalues and optionally the eigenvectors of a batch of Hermitian matrices A_l. More...

Public Member Functions
integer(kind(rocblas_status_success)) function	rocsolver_cheevd_batched_ (handle, evect, uplo, n, a, lda, d, strided, e, stridee, myinfo, batch_count)

integer(kind(rocblas_status_success)) function	rocsolver_cheevd_batched_rank_0 (handle, evect, uplo, n, a, lda, d, strided, e, stridee, myinfo, batch_count)

integer(kind(rocblas_status_success)) function	rocsolver_cheevd_batched_rank_1 (handle, evect, uplo, n, a, lda, d, strided, e, stridee, myinfo, batch_count)

Detailed Description

The HEEVD_BATCHED functions compute the eigenvalues and optionally the eigenvectors of a batch of Hermitian matrices A_l.

Note: The _64 interface accepts int64_t arguments, but the matrix dimensions n and lda must still fit within a 32-bit integer (less than 2^31). The internal tridiagonal reduction and back-transformation steps remain 32-bit, which bounds the supported size.

The eigenvalues are returned in ascending order. The eigenvectors are computed using a divide-and-conquer algorithm, depending on the value of evect. The computed eigenvectors are orthonormal.

Parameters

[in]	handle	- rocblas_handle.
[in]	evect	- `rocblas_evect`. Specifies whether the eigenvectors are to be computed. If evect is rocblas_evect_original, then the eigenvectors are computed. rocblas_evect_tridiagonal is not supported.
[in]	uplo	- rocblas_fill. Specifies whether the upper or lower part of the Hermitian matrices A_l is stored. If uplo indicates lower (or upper), then the upper (or lower) part of A_l is not used.
[in]	n	- rocblas_int. n >= 0. Number of rows and columns of matrices A_l.
[in,out]	A	- Array of pointers to type. Each pointer points to an array on the GPU of dimension lda*n. On entry, the matrices A_l. On exit, the eigenvectors of A_l if they were computed and the algorithm converged. Otherwise, the contents of A_l are destroyed.
[in]	lda	- rocblas_int. lda >= n. Specifies the leading dimension of matrices A_l.
[out]	D	- pointer to real type. Array on the GPU (the size depends on the value of strideD). The eigenvalues of A_l in increasing order.
[in]	strideD	- rocblas_stride. Stride from the start of one vector D_l to the next one D_(l+1). There is no restriction for the value of strideD. The normal use case is strideD >= n.
[out]	E	- pointer to real type. Array on the GPU (the size depends on the value of strideE). This array is used to work internally with the tridiagonal matrix T_l associated with A_l. On exit, if info[l] > 0, E_l contains the unconverged off-diagonal elements of T_l (or properly speaking, a tridiagonal matrix equivalent to T_l). The diagonal elements of this matrix are in D_l. Those that converged correspond to a subset of the eigenvalues of A_l (not necessarily ordered).
[in]	strideE	- rocblas_stride. Stride from the start of one vector E_l to the next one E_(l+1). There is no restriction for the value of strideE. The normal use case is strideE >= n.
[out]	myInfo	- pointer to rocblas_int. Array of batch_count integers on the GPU. If info[l] = 0, successful exit for matrix A_l. If info[l] = i > 0 and evect is rocblas_evect_none, the algorithm did not converge. i elements of E_l did not converge to zero. If info[l] = i > 0 and evect is rocblas_evect_original, the algorithm failed to compute an eigenvalue in the submatrix from [i/(n+1), i/(n+1)] to [i%(n+1), i%(n+1)].
[in]	batch_count	- rocblas_int. batch_count >= 0. Number of matrices in the batch.

Member Function/Subroutine Documentation