SRC/cgebak.f(3)

🎀 CGEBAK 🎀

okay bestie, this is the Library Functions Manual page for SRC/cgebak.f, and the manual-name energy is folded right in near the top. This whole page is serving CGEBAK — eigenvector backward-transformation realness. 💅

🎀 NAME 🎀

SRC/cgebak.f

✨ SYNOPSIS ✨

🧚 Functions/Subroutines 🧚

subroutine cgebak (job, side, n, ilo, ihi, scale, m, v, ldv, info)

CGEBAK

💅 Function/Subroutine Documentation 💅

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)

CGEBAK

🌸 Purpose 🌸

okay so 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. That's the whole serve. ✨

🍓 Parameters 🍓

JOB

JOB is CHARACTER*1. It 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

SIDE is CHARACTER*1:

• = 'R': V contains right eigenvectors;
• = 'L': V contains left eigenvectors.

N

N is INTEGER. It's the number of rows of the matrix V. N >= 0.

ILO

ILO is INTEGER.

IHI

IHI is 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

SCALE is REAL array, dimension (N). Details of the permutation and scaling factors, as returned by CGEBAL.

M

M is INTEGER. The number of columns of the matrix V. M >= 0.

V

V is 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

LDV is INTEGER. The leading dimension of the array V. LDV >= max(1,N).

INFO

INFO is 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.

🧚 Author 🧚

Generated automatically by Doxygen for LAPACK from the source code.

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💖 byeee bestie — shoutout to the footer: LAPACK Version 3.12.0, source SRC/cgebak.f(3); the date isn't printed on this one, but the version + source are fully accounted for. mwah! 💖