# rocsolver_chegv Interface Reference#

HIPFORT API Reference: hipfort_rocsolver::rocsolver_chegv Interface Reference
hipfort_rocsolver::rocsolver_chegv Interface Reference

HEGV computes the eigenvalues and (optionally) eigenvectors of a complex generalized hermitian-definite eigenproblem. More...

## Public Member Functions

integer(kind(rocblas_status_success)) function rocsolver_chegv_ (handle, itype, evect, uplo, n, A, lda, B, ldb, D, E, myInfo)

integer(kind(rocblas_status_success)) function rocsolver_chegv_full_rank (handle, itype, evect, uplo, n, A, lda, B, ldb, D, E, myInfo)

integer(kind(rocblas_status_success)) function rocsolver_chegv_rank_0 (handle, itype, evect, uplo, n, A, lda, B, ldb, D, E, myInfo)

integer(kind(rocblas_status_success)) function rocsolver_chegv_rank_1 (handle, itype, evect, uplo, n, A, lda, B, ldb, D, E, myInfo)

## Detailed Description

HEGV computes the eigenvalues and (optionally) eigenvectors of a complex generalized hermitian-definite eigenproblem.

The problem solved by this function is either of the form

$\begin{array}{cl} A X = \lambda B X & \: \text{1st form,}\newline A B X = \lambda X & \: \text{2nd form, or}\newline B A X = \lambda X & \: \text{3rd form,} \end{array}$

depending on the value of itype. The eigenvectors are computed depending on the value of evect.

When computed, the matrix Z of eigenvectors is normalized as follows:

$\begin{array}{cl} Z^H B Z=I & \: \text{if 1st or 2nd form, or}\newline Z^H B^{-1} Z=I & \: \text{if 3rd form.} \end{array}$

Parameters
 [in] handle rocblas_handle. [in] itype rocblas_eform. Specifies the form of the generalized eigenproblem. [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 parts of the matrices A and B are stored. If uplo indicates lower (or upper), then the upper (or lower) parts of A and B are not used. [in] n rocblas_int. n >= 0. The matrix dimensions. [in,out] A pointer to type. Array on the GPU of dimension lda*n. On entry, the hermitian matrix A. On exit, if evect is original, the normalized matrix Z of eigenvectors. If evect is none, then the upper or lower triangular part of the matrix A (including the diagonal) is destroyed, depending on the value of uplo. [in] lda rocblas_int. lda >= n. Specifies the leading dimension of A. [out] B pointer to type. Array on the GPU of dimension ldb*n. On entry, the hermitian positive definite matrix B. On exit, the triangular factor of B as returned by POTRF. [in] ldb rocblas_int. ldb >= n. Specifies the leading dimension of B. [out] D pointer to real type. Array on the GPU of dimension n. On exit, the eigenvalues in increasing order. [out] E pointer to real type. Array on the GPU of dimension n. This array is used to work internally with the tridiagonal matrix T associated with the reduced eigenvalue problem. On exit, if 0 < info <= n, it contains the unconverged off-diagonal elements of T (or properly speaking, a tridiagonal matrix equivalent to T). The diagonal elements of this matrix are in D; those that converged correspond to a subset of the eigenvalues (not necessarily ordered). [out] info pointer to a rocblas_int on the GPU. If info = 0, successful exit. If info = j <= n, j off-diagonal elements of an intermediate tridiagonal form did not converge to zero. If info = n + j, the leading minor of order j of B is not positive definite.

## ◆ rocsolver_chegv_()

 integer(kind(rocblas_status_success)) function hipfort_rocsolver::rocsolver_chegv::rocsolver_chegv_ ( type(c_ptr), value handle, integer(kind(rocblas_eform_ax)), value itype, integer(kind(rocblas_evect_original)), value evect, integer(kind(rocblas_fill_upper)), value uplo, integer(c_int), value n, type(c_ptr), value A, integer(c_int), value lda, type(c_ptr), value B, integer(c_int), value ldb, type(c_ptr), value D, type(c_ptr), value E, integer(c_int) myInfo )

## ◆ rocsolver_chegv_full_rank()

 integer(kind(rocblas_status_success)) function hipfort_rocsolver::rocsolver_chegv::rocsolver_chegv_full_rank ( type(c_ptr) handle, integer(kind(rocblas_eform_ax)) itype, integer(kind(rocblas_evect_original)) evect, integer(kind(rocblas_fill_upper)) uplo, integer(c_int) n, complex(c_float_complex), dimension(:,:), target A, integer(c_int) lda, complex(c_float_complex), dimension(:,:), target B, integer(c_int) ldb, real(c_float), dimension(:), target D, real(c_float), dimension(:), target E, integer(c_int) myInfo )

## ◆ rocsolver_chegv_rank_0()

 integer(kind(rocblas_status_success)) function hipfort_rocsolver::rocsolver_chegv::rocsolver_chegv_rank_0 ( type(c_ptr) handle, integer(kind(rocblas_eform_ax)) itype, integer(kind(rocblas_evect_original)) evect, integer(kind(rocblas_fill_upper)) uplo, integer(c_int) n, complex(c_float_complex), target A, integer(c_int) lda, complex(c_float_complex), target B, integer(c_int) ldb, real(c_float), target D, real(c_float), target E, integer(c_int) myInfo )

## ◆ rocsolver_chegv_rank_1()

 integer(kind(rocblas_status_success)) function hipfort_rocsolver::rocsolver_chegv::rocsolver_chegv_rank_1 ( type(c_ptr) handle, integer(kind(rocblas_eform_ax)) itype, integer(kind(rocblas_evect_original)) evect, integer(kind(rocblas_fill_upper)) uplo, integer(c_int) n, complex(c_float_complex), dimension(:), target A, integer(c_int) lda, complex(c_float_complex), dimension(:), target B, integer(c_int) ldb, real(c_float), dimension(:), target D, real(c_float), dimension(:), target E, integer(c_int) myInfo )

The documentation for this interface was generated from the following file: