heevr#

Functions

void cheevr(
    const char*          jobz,
    const char*          range,
    const char*          uplo,
    const INT            n,
          c64*  restrict A,
    const INT            lda,
    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,
          INT*  restrict isuppz,
          c64*  restrict work,
    const INT            lwork,
          f32*  restrict rwork,
    const INT            lrwork,
          INT*  restrict iwork,
    const INT            liwork,
          INT*           info
);
void cheevr(const char *jobz, const char *range, const char *uplo, const INT n, c64 *restrict A, const INT lda, 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, INT *restrict isuppz, c64 *restrict work, const INT lwork, f32 *restrict rwork, const INT lrwork, INT *restrict iwork, const INT liwork, INT *info)#

CHEEVR computes selected eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix A.

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

CHEEVR first reduces the matrix A to tridiagonal form T with a call to CHETRD. Then, whenever possible, CHEEVR calls CSTEMR to compute the eigenspectrum using Relatively Robust Representations.

Parameters

in
jobz

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

in
range

= ‘A’: all eigenvalues will be found. = ‘V’: all eigenvalues in (VL,VU] will be found. = ‘I’: the IL-th through IU-th eigenvalues will be found.

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.

inout
A

On entry, the Hermitian matrix A. On exit, the lower triangle (if uplo=’L’) or the upper triangle (if uplo=’U’) is destroyed.

in
lda

The leading dimension of A. lda >= max(1, n).

in
vl

If RANGE=’V’, lower bound of interval.

in
vu

If RANGE=’V’, upper bound of interval. VL < VU.

in
il

If RANGE=’I’, index of smallest eigenvalue.

in
iu

If RANGE=’I’, index of largest eigenvalue.

in
abstol

Absolute error tolerance for eigenvalues.

out
m

The total number of eigenvalues found.

out
W

The first M elements contain the selected eigenvalues in ascending order.

out
Z

If JOBZ = ‘V’, the first M columns contain the orthonormal eigenvectors. If JOBZ = ‘N’, Z is not referenced.

in
ldz

Leading dimension of Z. LDZ >= 1, and if JOBZ = ‘V’, LDZ >= N.

out
isuppz

Support of eigenvectors in Z. Dimension (2*max(1,M)).

out
work

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

in
lwork

Length of work. If -1, workspace query.

out
rwork

Single precision workspace. On exit, rwork[0] = optimal LRWORK.

in
lrwork

Length of rwork. If -1, workspace query.

out
iwork

Integer workspace. On exit, iwork[0] = optimal LIWORK.

in
liwork

Length of iwork. If -1, workspace query.

out
info

  • = 0: successful exit

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

  • > 0: Internal error

Functions

void zheevr(
    const char*          jobz,
    const char*          range,
    const char*          uplo,
    const INT            n,
          c128* restrict A,
    const INT            lda,
    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,
          INT*  restrict isuppz,
          c128* restrict work,
    const INT            lwork,
          f64*  restrict rwork,
    const INT            lrwork,
          INT*  restrict iwork,
    const INT            liwork,
          INT*           info
);
void zheevr(const char *jobz, const char *range, const char *uplo, const INT n, c128 *restrict A, const INT lda, 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, INT *restrict isuppz, c128 *restrict work, const INT lwork, f64 *restrict rwork, const INT lrwork, INT *restrict iwork, const INT liwork, INT *info)#

ZHEEVR computes selected eigenvalues and, optionally, eigenvectors of a complex Hermitian matrix A.

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

ZHEEVR first reduces the matrix A to tridiagonal form T with a call to ZHETRD. Then, whenever possible, ZHEEVR calls ZSTEMR to compute the eigenspectrum using Relatively Robust Representations.

Parameters

in
jobz

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

in
range

= ‘A’: all eigenvalues will be found. = ‘V’: all eigenvalues in (VL,VU] will be found. = ‘I’: the IL-th through IU-th eigenvalues will be found.

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.

inout
A

On entry, the Hermitian matrix A. On exit, the lower triangle (if uplo=’L’) or the upper triangle (if uplo=’U’) is destroyed.

in
lda

The leading dimension of A. lda >= max(1, n).

in
vl

If RANGE=’V’, lower bound of interval.

in
vu

If RANGE=’V’, upper bound of interval. VL < VU.

in
il

If RANGE=’I’, index of smallest eigenvalue.

in
iu

If RANGE=’I’, index of largest eigenvalue.

in
abstol

Absolute error tolerance for eigenvalues.

out
m

The total number of eigenvalues found.

out
W

The first M elements contain the selected eigenvalues in ascending order.

out
Z

If JOBZ = ‘V’, the first M columns contain the orthonormal eigenvectors. If JOBZ = ‘N’, Z is not referenced.

in
ldz

Leading dimension of Z. LDZ >= 1, and if JOBZ = ‘V’, LDZ >= N.

out
isuppz

Support of eigenvectors in Z. Dimension (2*max(1,M)).

out
work

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

in
lwork

Length of work. If -1, workspace query.

out
rwork

Double precision workspace. On exit, rwork[0] = optimal LRWORK.

in
lrwork

Length of rwork. If -1, workspace query.

out
iwork

Integer workspace. On exit, iwork[0] = optimal LIWORK.

in
liwork

Length of iwork. If -1, workspace query.

out
info

  • = 0: successful exit

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

  • > 0: Internal error