1elpa_skew_eigenvalues(3)   Library Functions Manual   elpa_skew_eigenvalues(3)
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NAME

6       elpa_skew_eigenvalues - computes the eigenvalues of a real skew-
7       symmetric matrix
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SYNOPSIS

11   FORTRAN INTERFACE
12       use elpa
13       class(elpa_t), pointer :: elpa
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15       call elpa%skew_eigenvalues (a, ev, error)
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17       With the definitions of the input and output variables:
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19       class(elpa_t) :: elpa  ! returns an instance of the ELPA object
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21       datatype :: a
22              The matrix a for which the eigenvalues should be computed. The
23              dimensions of matrix a must be set BEFORE with the methods
24              elpa_set(3) and elpa_setup(3). The datatype of the matrix can be
25              one of "real(kind=c_double)" or "real(kind=c_float)". The matrix
26              has to be skew-symmetric, this is not checked by the routine.
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28       datatype :: ev
29              The vector ev where the eigenvalues will be stored in ascending
30              order. The datatype of the vector ev can be either
31              "real(kind=c_double)", or "real(kind=c_float)", depending of the
32              datatype of the matrix.
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34       integer, optional :: error
35              The return error code of the function. Should be "ELPA_OK". The
36              error code can be querried with the function elpa_strerr(3)
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39   C INTERFACE
40       #include <elpa/elpa.h>
41       elpa_t handle;
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43       void elpa_skew_eigenvalues(elpa_t handle, datatype *a, datatype *ev,
44       int *error);
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46       With the definitions of the input and output variables:
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49       elpa_t handle;
50              The handle to the ELPA object
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52       datatype *a;
53              The matrix a for which the eigenvalues should be computed. The
54              dimensions of the matrix must be set BEFORE with the methods
55              elpa_set(3) and elpa_setup(3). The datatype can be one of
56              "double" or "float".
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58       datatype *ev;
59              The storage for the computed eigenvalues. Eigenvalues will be
60              stored in ascendig order. The datatype can be either "double" or
61              "float". Note that the eigenvalues of complex hermitian matrices
62              are also real. The matrix has to be skew-symmetric, this is not
63              checked by the routine.
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65       int *error;
66              The error code of the function. Should be "ELPA_OK". The error
67              codes can be querried with elpa_strerr(3)
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DESCRIPTION

71       Compute the eigenvalues of a real skew-symmetric matrix.The functions
72       elpa_init(3), elpa_allocate(3), elpa_set(3), and elpa_setup(3) must be
73       called BEFORE elpa_skew_eigenvalues can be called.
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SEE ALSO

76       elpa2_print_kernels(1) elpa_init(3) elpa_allocate(3) elpa_set(3)
77       elpa_setup(3) elpa_strerr(3) elpa_eigenvectors(3)
78       elpa_skew_eigenvectors(3) elpa_eigenvalues(3) elpa_cholesky(3)
79       elpa_invert_triangular(3) elpa_solve_tridiagonal(3) elpa_eigenvalues(3)
80       elpa_uninit(3) elpa_deallocate(3)
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84ELPA                            Thur Nov 7 2019       elpa_skew_eigenvalues(3)
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