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elpa_eigenvalues_double(3) Library Functions Manual elpa_eigenvalues_double(3)

NAME

elpa_eigenvalues_double - computes all eigenvalues λ for a real symmetric eigenproblem: A*Q = λ*Q

SYNOPSIS

FORTRAN INTERFACE

use elpa
class(elpa_t), pointer :: elpa_handle

call elpa_handle%eigenvalues_double (a, ev, error)

With the definitions of the input and output variables:

An instance of the ELPA object.
The local part of the host/device matrix A for which the eigenvalues should be computed. The dimensions of matrix a must be set BEFORE with the methods elpa_set(3) and elpa_setup(3). The global matrix has to be symmetric, this is not checked by the routine. In case of a GPU build a can be a pointer to the device memory.
The global array where the eigenvalues λ will be stored in ascending order. In case of a GPU build ev can be a pointer to the device memory.
The return error code of the function. Should be "ELPA_OK". The error code can be queried with the function elpa_strerr(3)

C/C++ INTERFACE

#include <elpa/elpa.h>
elpa_t elpa_handle;

void elpa_eigenvalues_double(elpa_t elpa_handle, double *a, double *ev, int *error);

With the definitions of the input and output variables:

The handle to the ELPA object
The local part of the host/device matrix A for which the eigenvalues should be computed. The dimensions of matrix a must be set BEFORE with the methods elpa_set(3) and elpa_setup(3). The global matrix A has to be symmetric, this is not checked by the routine. In case of a GPU build a can be a pointer to the device memory.
The array where the eigenvalues λ will be stored in ascending order. Eigenvalues will be stored in ascending order. In case of a GPU build ev can be a pointer to the device memory.

The error code of the function. Should be "ELPA_OK". The error codes can be queried with elpa_strerr(3)

DESCRIPTION

Computes the eigenvalues of a double precision real symmetric matrix. The functions elpa_init(3), elpa_allocate(3), elpa_set(3), and elpa_setup(3) must be called BEFORE elpa_eigenvalues_double can be called.

SEE ALSO

elpa2_print_kernels(1) elpa_init(3) elpa_allocate(3) elpa_set(3) elpa_setup(3) elpa_strerr(3) elpa_skew_eigenvalues(3) elpa_eigenvectors(3) elpa_skew_eigenvectors(3) elpa_cholesky(3) elpa_invert_triangular(3) elpa_solve_tridiagonal(3) elpa_eigenvalues(3) elpa_uninit(3) elpa_deallocate(3)

Thu Nov 28 2024 ELPA