rocsolver_ssteqr Interface Reference

rocsolver_ssteqr Interface Reference#

HIPFORT API Reference: hipfort_rocsolver::rocsolver_ssteqr Interface Reference

Public Member Functions
integer(kind(rocblas_status_success)) function	rocsolver_ssteqr_full_rank (handle, evect, n, D, E, C, ldc, myInfo)


integer(kind(rocblas_status_success)) function	rocsolver_ssteqr_ (handle, evect, n, D, E, C, ldc, myInfo)

integer(kind(rocblas_status_success)) function	rocsolver_ssteqr_rank_0 (handle, evect, n, D, E, C, ldc, myInfo)

integer(kind(rocblas_status_success)) function	rocsolver_ssteqr_rank_1 (handle, evect, n, D, E, C, ldc, myInfo)

Detailed Description

!

STEQR computes the eigenvalues and (optionally) eigenvectors of a symmetric tridiagonal matrix.

The eigenvalues of the symmetric tridiagonal matrix are computed by the implicit QLQR algorithm, and returned in increasing order.

The matrix is not represented explicitly, but rather as the array of diagonal elements D and the array of symmetric off-diagonal elements E. When D and E correspond to the tridiagonal form of a full symmetricHermitian matrix, as returned by, e.g., SYTRD or HETRD, the eigenvectors of the original matrix can also be computed, depending on the value of evect.

Parameters

[in]	handle	rocblas_handle.
[in]	evect	#rocblas_evect. Specifies how the eigenvectors are computed.
[in]	n	rocblas_int. n >= 0. The number of rows and columns of the tridiagonal matrix.
[in,out]	D	pointer to real type. Array on the GPU of dimension n. On entry, the diagonal elements of the tridiagonal matrix. On exit, if info = 0, the eigenvalues in increasing order. If info > 0, the diagonal elements of a tridiagonal matrix that is similar to the original matrix (i.e. has the same eigenvalues).
[in,out]	E	pointer to real type. Array on the GPU of dimension n-1. On entry, the off-diagonal elements of the tridiagonal matrix. On exit, if info = 0, this array converges to zero. If info > 0, the off-diagonal elements of a tridiagonal matrix that is similar to the original matrix (i.e. has the same eigenvalues).
[in,out]	C	pointer to type. Array on the GPU of dimension ldcn. On entry, if evect is original, the orthogonalunitary matrix used for the reduction to tridiagonal form as returned by, e.g., ORGTR or UNGTR. On exit, it is overwritten with the eigenvectors of the original symmetricHermitian matrix (if evect is original), or the eigenvectors of the tridiagonal matrix (if evect is tridiagonal). (Not referenced if evect is none).
[in]	ldc	rocblas_int. ldc >= n if evect is original or tridiagonal. Specifies the leading dimension of C. (Not referenced if evect is none).
[out]	info	pointer to a rocblas_int on the GPU. If info = 0, successful exit. If info = i > 0, STEQR did not converge. i elements of E did not converge to zero.

Member Function/Subroutine Documentation