sbev

ssbev

Functions

void ssbev(
    const char*          jobz,
    const char*          uplo,
    const INT            n,
    const INT            kd,
          f32*  restrict AB,
    const INT            ldab,
          f32*  restrict W,
          f32*  restrict Z,
    const INT            ldz,
          f32*  restrict work,
          INT*           info
);

void ssbev(const char *jobz, const char *uplo, const INT n, const INT kd, f32 *restrict AB, const INT ldab, f32 *restrict W, f32 *restrict Z, const INT ldz, f32 *restrict work, INT *info)

SSBEV computes all the eigenvalues and, optionally, eigenvectors of a real symmetric band matrix A.

Parameters

in

jobz

= ‘N’: Compute eigenvalues only = ‘V’: Compute eigenvalues and eigenvectors

in

uplo

= ‘U’: Upper triangle of A is stored = ‘L’: Lower triangle of A is stored

in

n

The order of the matrix A. n >= 0.

in

kd

The number of super-diagonals (if uplo=’U’) or sub-diagonals (if uplo=’L’). kd >= 0.

inout

AB

The banded matrix A. Array of dimension (ldab, n). On exit, overwritten by values generated during reduction.

in

ldab

The leading dimension of AB. ldab >= kd+1.

out

W

The eigenvalues in ascending order. Array of dimension (n).

out

Z

If jobz=’V’, the orthonormal eigenvectors. Array of dimension (ldz, n).

in

ldz

The leading dimension of Z. ldz >= 1, and >= n if jobz=’V’.

out

work

Workspace array of dimension (max(1, 3*n-2)).

out

info

• = 0: successful exit

• < 0: if info = -i, the i-th argument had an illegal value

• > 0: if info = i, the algorithm failed to converge

dsbev

Functions

void dsbev(
    const char*          jobz,
    const char*          uplo,
    const INT            n,
    const INT            kd,
          f64*  restrict AB,
    const INT            ldab,
          f64*  restrict W,
          f64*  restrict Z,
    const INT            ldz,
          f64*  restrict work,
          INT*           info
);

void dsbev(const char *jobz, const char *uplo, const INT n, const INT kd, f64 *restrict AB, const INT ldab, f64 *restrict W, f64 *restrict Z, const INT ldz, f64 *restrict work, INT *info)

DSBEV computes all the eigenvalues and, optionally, eigenvectors of a real symmetric band matrix A.

Parameters

in

jobz

= ‘N’: Compute eigenvalues only = ‘V’: Compute eigenvalues and eigenvectors

in

uplo

= ‘U’: Upper triangle of A is stored = ‘L’: Lower triangle of A is stored

in

n

The order of the matrix A. n >= 0.

in

kd

The number of super-diagonals (if uplo=’U’) or sub-diagonals (if uplo=’L’). kd >= 0.

inout

AB

The banded matrix A. Array of dimension (ldab, n). On exit, overwritten by values generated during reduction.

in

ldab

The leading dimension of AB. ldab >= kd+1.

out

W

The eigenvalues in ascending order. Array of dimension (n).

out

Z

If jobz=’V’, the orthonormal eigenvectors. Array of dimension (ldz, n).

in

ldz

The leading dimension of Z. ldz >= 1, and >= n if jobz=’V’.

out

work

Workspace array of dimension (max(1, 3*n-2)).

out

info

• = 0: successful exit

• < 0: if info = -i, the i-th argument had an illegal value

• > 0: if info = i, the algorithm failed to converge