gebak(3)

📦
version 3.12.1 · 9 versions
, in arch rolling

💅 NAME 💅

Okay bestie, welcome to gebak(3) — yes, that's the Library Functions Manual page for gebak, and the whole entire vibe of it is:

gebak — gebak: back-transform eigvec ✨

That's it. That's the name section. It's giving "short and iconic." 🎀

✨ SYNOPSIS ✨

🦋 Functions

So there's not one, not two, but four subroutines on this roster, and they're all twinsies with different precision energy. Here they are, exactly as they appear, no cap:

  • subroutine cgebak (job, side, n, ilo, ihi, scale, m, v, ldv, info) — the complex one, aka CGEBAK 💜
  • subroutine dgebak (job, side, n, ilo, ihi, scale, m, v, ldv, info) — the double precision one, aka DGEBAK 🔥
  • subroutine sgebak (job, side, n, ilo, ihi, scale, m, v, ldv, info) — the single precision one, aka SGEBAK 🌸
  • subroutine zgebak (job, side, n, ilo, ihi, scale, m, v, ldv, info) — the double complex one, aka ZGEBAK 👑

Like, look at that. Same argument list every single time: job, side, n, ilo, ihi, scale, m, v, ldv, info. Consistent queen behavior. 👑 Not me being obsessed with a uniform interface fr fr.

🌈 Detailed Description 🌈

Okay so this is the part where the description would go — and bestie, this section is literally just sitting there with no body text in part 1. 😭 It's giving "placeholder main character energy." The heading exists, the vibes are immaculate, the paragraphs have not arrived yet.

More parts are coming, so don't go anywhere — the story of gebak is not over. 🫶

✨ FUNCTION DOCUMENTATION ✨

okay bestie, this is where the four gebak siblings show up — same core energy, different precision/type. Let’s get into it 💅

💅 cgebak — CGEBAK 💅

subroutine cgebak (character job, character side, integer n, integer ilo,
    integer ihi, real, dimension( * ) scale, integer m, complex, dimension(
    ldv, * ) v, integer ldv, integer info)

💖 Purpose 💖

CGEBAK forms the right or left eigenvectors of a complex general matrix by backward transformation on the computed eigenvectors of the balanced matrix output by CGEBAL. iconic behavior, no cap 🦋

🎀 Parameters 🎀

  • JOB — CHARACTER*1. Specifies the type of backward transformation required:
    • 'N': do nothing, return immediately;
    • 'P': do backward transformation for permutation only;
    • 'S': do backward transformation for scaling only;
    • 'B': do backward transformations for both permutation and scaling.

JOB must be the same as the argument JOB supplied to CGEBAL.

  • SIDE — CHARACTER*1.
    • 'R': V contains right eigenvectors;
    • 'L': V contains left eigenvectors.
  • N — INTEGER. The number of rows of the matrix V. N >= 0.
  • ILO — INTEGER.
  • IHI — INTEGER. The integers ILO and IHI determined by CGEBAL. 1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.
  • SCALE — REAL array, dimension (N). Details of the permutation and scaling factors, as returned by CGEBAL.
  • M — INTEGER. The number of columns of the matrix V. M >= 0.
  • V — COMPLEX array, dimension (LDV,M). On entry, the matrix of right or left eigenvectors to be transformed, as returned by CHSEIN or CTREVC. On exit, V is overwritten by the transformed eigenvectors.
  • LDV — INTEGER. The leading dimension of the array V. LDV >= max(1,N).
  • INFO — INTEGER.
    • = 0: successful exit;
    • < 0: if INFO = -i, the i-th argument had an illegal value.

🫶 Author 🫶

  • Univ. of Tennessee
  • Univ. of California Berkeley
  • Univ. of Colorado Denver
  • NAG Ltd.

Definition at line 129 of file cgebak.f.

🦋 dgebak — DGEBAK 🦋

subroutine dgebak (character job, character side, integer n, integer ilo,
    integer ihi, double precision, dimension( * ) scale, integer m, double
    precision, dimension( ldv, * ) v, integer ldv, integer info)

💖 Purpose 💖

DGEBAK forms the right or left eigenvectors of a real general matrix by backward transformation on the computed eigenvectors of the balanced matrix output by DGEBAL. real-world glow-up, literally ✨

🎀 Parameters 🎀

  • JOB — CHARACTER*1. Specifies the type of backward transformation required:
    • 'N': do nothing, return immediately;
    • 'P': do backward transformation for permutation only;
    • 'S': do backward transformation for scaling only;
    • 'B': do backward transformations for both permutation and scaling.

JOB must be the same as the argument JOB supplied to DGEBAL.

  • SIDE — CHARACTER*1.
    • 'R': V contains right eigenvectors;
    • 'L': V contains left eigenvectors.
  • N — INTEGER. The number of rows of the matrix V. N >= 0.
  • ILO — INTEGER.
  • IHI — INTEGER. The integers ILO and IHI determined by DGEBAL. 1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.
  • SCALE — DOUBLE PRECISION array, dimension (N). Details of the permutation and scaling factors, as returned by DGEBAL.
  • M — INTEGER. The number of columns of the matrix V. M >= 0.
  • V — DOUBLE PRECISION array, dimension (LDV,M). On entry, the matrix of right or left eigenvectors to be transformed, as returned by DHSEIN or DTREVC. On exit, V is overwritten by the transformed eigenvectors.
  • LDV — INTEGER. The leading dimension of the array V. LDV >= max(1,N).
  • INFO — INTEGER.
    • = 0: successful exit;
    • < 0: if INFO = -i, the i-th argument had an illegal value.

🫶 Author 🫶

  • Univ. of Tennessee
  • Univ. of California Berkeley
  • Univ. of Colorado Denver
  • NAG Ltd.

Definition at line 128 of file dgebak.f.

🌸 sgebak — SGEBAK 🌸

subroutine sgebak (character job, character side, integer n, integer ilo,
    integer ihi, real, dimension( * ) scale, integer m, real, dimension(
    ldv, * ) v, integer ldv, integer info)

💖 Purpose 💖

SGEBAK forms the right or left eigenvectors of a real general matrix by backward transformation on the computed eigenvectors of the balanced matrix output by SGEBAL. same vibe, single precision, still slaying 💅

🎀 Parameters 🎀

  • JOB — CHARACTER*1. Specifies the type of backward transformation required:
    • 'N': do nothing, return immediately;
    • 'P': do backward transformation for permutation only;
    • 'S': do backward transformation for scaling only;
    • 'B': do backward transformations for both permutation and scaling.

JOB must be the same as the argument JOB supplied to SGEBAL.

  • SIDE — CHARACTER*1.
    • 'R': V contains right eigenvectors;
    • 'L': V contains left eigenvectors.
  • N — INTEGER. The number of rows of the matrix V. N >= 0.
  • ILO — INTEGER.
  • IHI — INTEGER. The integers ILO and IHI determined by SGEBAL. 1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.
  • SCALE — REAL array, dimension (N). Details of the permutation and scaling factors, as returned by SGEBAL.
  • M — INTEGER. The number of columns of the matrix V. M >= 0.
  • V — REAL array, dimension (LDV,M). On entry, the matrix of right or left eigenvectors to be transformed, as returned by SHSEIN or STREVC. On exit, V is overwritten by the transformed eigenvectors.
  • LDV — INTEGER. The leading dimension of the array V. LDV >= max(1,N).
  • INFO — INTEGER.
    • = 0: successful exit;
    • < 0: if INFO = -i, the i-th argument had an illegal value.

🫶 Author 🫶

  • Univ. of Tennessee
  • Univ. of California Berkeley
  • Univ. of Colorado Denver
  • NAG Ltd.

Definition at line 128 of file sgebak.f.

👑 zgebak — ZGEBAK 👑

subroutine zgebak (character job, character side, integer n, integer ilo,
    integer ihi, double precision, dimension( * ) scale, integer m,
    complex*16, dimension( ldv, * ) v, integer ldv, integer info)

💖 Purpose 💖

ZGEBAK forms the right or left eigenvectors of a complex general matrix by backward transformation on the computed eigenvectors of the balanced matrix output by ZGEBAL. double precision complex main character energy, periodt 🌈

🎀 Parameters 🎀

  • JOB — CHARACTER*1. Specifies the type of backward transformation required:
    • 'N': do nothing, return immediately;
    • 'P': do backward transformation for permutation only;
    • 'S': do backward transformation for scaling only;
    • 'B': do backward transformations for both permutation and scaling.

JOB must be the same as the argument JOB supplied to ZGEBAL.

  • SIDE — CHARACTER*1.
    • 'R': V contains right eigenvectors;
    • 'L': V contains left eigenvectors.
  • N — INTEGER. The number of rows of the matrix V. N >= 0.
  • ILO — INTEGER.
  • IHI — INTEGER. The integers ILO and IHI determined by ZGEBAL. 1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.
  • SCALE — DOUBLE PRECISION array, dimension (N). Details of the permutation and scaling factors, as returned by ZGEBAL.
  • M — INTEGER. The number of columns of the matrix V. M >= 0.
  • V — COMPLEX*16 array, dimension (LDV,M). On entry, the matrix of right or left eigenvectors to be transformed, as returned by ZHSEIN or ZTREVC. On exit, V is overwritten by the transformed eigenvectors.
  • LDV — INTEGER. The leading dimension of the array V. LDV >= max(1,N).
  • INFO — INTEGER.
    • = 0: successful exit;
    • < 0: if INFO = -i, the i-th argument had an illegal value.

🫶 Author 🫶

  • Univ. of Tennessee
  • Univ. of California Berkeley
  • Univ. of Colorado Denver
  • NAG Ltd.

Definition at line 129 of file zgebak.f.

🪄 Author (page-level) 🪄

Generated automatically by Doxygen for LAPACK from the source code.

And that’s the whole GEBAK crew, bestie! 🌟 Final footer vibes: LAPACK Version 3.12.0, gebak(3), with the source/version/date footer deets doing their thing — mwah, go slay those eigenvectors 💋👑

📦 where this page comes from