hbevx_2stage#

Functions

void chbevx_2stage(
    const char*          jobz,
    const char*          range,
    const char*          uplo,
    const INT            n,
    const INT            kd,
          c64*  restrict AB,
    const INT            ldab,
          c64*  restrict Q,
    const INT            ldq,
    const f32            vl,
    const f32            vu,
    const INT            il,
    const INT            iu,
    const f32            abstol,
          INT*           m,
          f32*  restrict W,
          c64*  restrict Z,
    const INT            ldz,
          c64*  restrict work,
    const INT            lwork,
          f32*  restrict rwork,
          INT*  restrict iwork,
          INT*  restrict ifail,
          INT*           info
);
void chbevx_2stage(const char *jobz, const char *range, const char *uplo, const INT n, const INT kd, c64 *restrict AB, const INT ldab, c64 *restrict Q, const INT ldq, const f32 vl, const f32 vu, const INT il, const INT iu, const f32 abstol, INT *m, f32 *restrict W, c64 *restrict Z, const INT ldz, c64 *restrict work, const INT lwork, f32 *restrict rwork, INT *restrict iwork, INT *restrict ifail, INT *info)#

CHBEVX_2STAGE computes selected eigenvalues and, optionally, eigenvectors of a complex Hermitian band matrix A using the 2stage technique for the reduction to tridiagonal.

Eigenvalues and eigenvectors can be selected by specifying either a range of values or a range of indices for the desired eigenvalues.

Parameters

in
jobz

= ‘N’: eigenvalues only; = ‘V’: not available in this release.

in
range

= ‘A’: all eigenvalues; = ‘V’: eigenvalues in (vl,vu]; = ‘I’: il-th through iu-th eigenvalues.

in
uplo

= ‘U’: upper triangle stored; = ‘L’: lower triangle stored

in
n

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

in
kd

Number of super/sub-diagonals. kd >= 0.

inout
AB

Complex band matrix, overwritten on exit.

in
ldab

Leading dimension of AB. ldab >= kd+1.

out
Q

Unitary matrix if jobz=’V’; not referenced if jobz=’N’.

in
ldq

Leading dimension of Q. ldq >= 1, or ldq >= n if jobz=’V’.

in
vl

Lower bound if range=’V’.

in
vu

Upper bound if range=’V’. vl < vu.

in
il

Smallest eigenvalue index if range=’I’.

in
iu

Largest eigenvalue index if range=’I’.

in
abstol

Absolute error tolerance for eigenvalues.

out
m

Number of eigenvalues found.

out
W

Selected eigenvalues in ascending order.

out
Z

Eigenvectors if jobz=’V’; not referenced if jobz=’N’.

in
ldz

Leading dimension of Z. ldz >= 1, or ldz >= n if jobz=’V’.

out
work

Complex workspace. On exit, work[0] = optimal LWORK.

in
lwork

Length of work. If -1, workspace query.

out
rwork

Single precision workspace, dimension (7*n).

out
iwork

Integer workspace, dimension (5*n).

out
ifail

Indices of eigenvectors that failed to converge.

out
info

  • = 0: success; < 0: illegal argument; > 0: convergence failure.

Functions

void zhbevx_2stage(
    const char*          jobz,
    const char*          range,
    const char*          uplo,
    const INT            n,
    const INT            kd,
          c128* restrict AB,
    const INT            ldab,
          c128* restrict Q,
    const INT            ldq,
    const f64            vl,
    const f64            vu,
    const INT            il,
    const INT            iu,
    const f64            abstol,
          INT*           m,
          f64*  restrict W,
          c128* restrict Z,
    const INT            ldz,
          c128* restrict work,
    const INT            lwork,
          f64*  restrict rwork,
          INT*  restrict iwork,
          INT*  restrict ifail,
          INT*           info
);
void zhbevx_2stage(const char *jobz, const char *range, const char *uplo, const INT n, const INT kd, c128 *restrict AB, const INT ldab, c128 *restrict Q, const INT ldq, const f64 vl, const f64 vu, const INT il, const INT iu, const f64 abstol, INT *m, f64 *restrict W, c128 *restrict Z, const INT ldz, c128 *restrict work, const INT lwork, f64 *restrict rwork, INT *restrict iwork, INT *restrict ifail, INT *info)#

ZHBEVX_2STAGE computes selected eigenvalues and, optionally, eigenvectors of a complex Hermitian band matrix A using the 2stage technique for the reduction to tridiagonal.

Eigenvalues and eigenvectors can be selected by specifying either a range of values or a range of indices for the desired eigenvalues.

Parameters

in
jobz

= ‘N’: eigenvalues only; = ‘V’: not available in this release.

in
range

= ‘A’: all eigenvalues; = ‘V’: eigenvalues in (vl,vu]; = ‘I’: il-th through iu-th eigenvalues.

in
uplo

= ‘U’: upper triangle stored; = ‘L’: lower triangle stored

in
n

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

in
kd

Number of super/sub-diagonals. kd >= 0.

inout
AB

Complex band matrix, overwritten on exit.

in
ldab

Leading dimension of AB. ldab >= kd+1.

out
Q

Unitary matrix if jobz=’V’; not referenced if jobz=’N’.

in
ldq

Leading dimension of Q. ldq >= 1, or ldq >= n if jobz=’V’.

in
vl

Lower bound if range=’V’.

in
vu

Upper bound if range=’V’. vl < vu.

in
il

Smallest eigenvalue index if range=’I’.

in
iu

Largest eigenvalue index if range=’I’.

in
abstol

Absolute error tolerance for eigenvalues.

out
m

Number of eigenvalues found.

out
W

Selected eigenvalues in ascending order.

out
Z

Eigenvectors if jobz=’V’; not referenced if jobz=’N’.

in
ldz

Leading dimension of Z. ldz >= 1, or ldz >= n if jobz=’V’.

out
work

Complex workspace. On exit, work[0] = optimal LWORK.

in
lwork

Length of work. If -1, workspace query.

out
rwork

Double precision workspace, dimension (7*n).

out
iwork

Integer workspace, dimension (5*n).

out
ifail

Indices of eigenvectors that failed to converge.

out
info

  • = 0: success; < 0: illegal argument; > 0: convergence failure.