ZHECON(3)

💅 ZHECON(3) — Library Functions Manual ✨

okay bestie, welcome to the Library Functions Manual entry for ZHECON(3) — yes, the whole page is literally a glow-up for one LAPACK routine, and honestly? iconic. 🫶

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🌸 NAME 🌸

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/zhecon.f

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🦋 SYNOPSIS 🦋

Functions/Subroutines

subroutine ZHECON (uplo, n, a, lda, ipiv, anorm, rcond, work, info)
    ZHECON

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✨ Function/Subroutine Documentation ✨

The main-character signature is giving full type detail, no crumbs:

subroutine ZHECON (character uplo, integer n, complex*16, dimension( lda, *
    ) a, integer lda, integer, dimension( * ) ipiv, double precision anorm,
    double precision rcond, complex*16, dimension( * ) work, integer info)
    ZHECON

💖 Purpose 💖

So like, ZHECON estimates the reciprocal of the condition number of a complex Hermitian matrix A using the factorization A = U*D*U**H or A = L*D*L**H computed by ZHETRF.

An estimate is obtained for norm(inv(A)), and the reciprocal of the condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))).

That's the whole vibe. reciprocal condition number realness. 💜

🎀 Parameters 🎀

UPLO

• UPLO is CHARACTER*1 — specifies whether the details of the factorization are stored as an upper or lower triangular matrix.
  • = 'U': Upper triangular, form is A = U*D*U**H;
  • = 'L': Lower triangular, form is A = L*D*L**H.

N

• N is INTEGER — the order of the matrix A. N >= 0.

A

• A is COMPLEX*16 array, dimension (LDA,N) — the block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by ZHETRF.

LDA

• LDA is INTEGER — the leading dimension of the array A. LDA >= max(1,N).

IPIV

• IPIV is INTEGER array, dimension (N) — details of the interchanges and the block structure of D as determined by ZHETRF.

ANORM

• ANORM is DOUBLE PRECISION — the 1-norm of the original matrix A.

RCOND

• RCOND is DOUBLE PRECISION — the reciprocal of the condition number of the matrix A, computed as RCOND = 1/(ANORM * AINVNM), where AINVNM is an estimate of the 1-norm of inv(A) computed in this routine.

WORK

• WORK is COMPLEX*16 array, dimension (2*N) — literally the workspace, slay. 🧚

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 123 of file zhecon.f.

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💫 Author 💫

Generated automatically by Doxygen for LAPACK from the source code.

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sign-off time, bestie: this page is rockin' LAPACK Version 3.12.0, source path /home/abui...RC/zhecon.f(3), and the page didn't give me a date so I'm not making one up — fr fr, no invented dates on my watch. 💖✨