SRC/zhpcon.f(3)

📦
version 3.12.1 · 7 versions
, in arch rolling

💖 NAME 💖

SRC/zhpcon.f — okay bestie, this is the SRC/zhpcon.f(3) page from the Library Functions Manual, and it’s lowkey all about ZHPCON 💅✨

🦋 SYNOPSIS 🦋

Functions/Subroutines

   subroutine zhpcon (uplo, n, ap, ipiv, anorm, rcond, work, info)
           ZHPCON

🌸 Function/Subroutine Documentation 🌸

   subroutine zhpcon (character uplo, integer n, complex*16, dimension( * ) ap,
       integer, dimension( * ) ipiv, double precision anorm, double precision
       rcond, complex*16, dimension( * ) work, integer info)
       ZHPCON

🎀 Purpose 🎀

So ZHPCON estimates the reciprocal of the condition number of a complex Hermitian packed matrix A using the factorization A = U*D*U**H or A = L*D*L**H computed by ZHPTRF. Obsessed with a good factorization? Same.

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

💅 Parameters 💅

UPLO

UPLO is CHARACTER*1 — it specifies whether the details of the factorization are stored as an upper or lower triangular matrix, bestie.

  • = '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. And the rule is N >= 0, no cap 🫶

AP

AP is COMPLEX*16 array, dimension (N*(N+1)/2) — it holds the block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by ZHPTRF, stored as a packed triangular matrix. It’s giving very structured main character energy 🔥

IPIV

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

ANORM

ANORM is DOUBLE PRECISION — the 1-norm of the original matrix A. Literally the norm bestie 💜

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. The math is mathing ✨

WORK

WORK is COMPLEX*16 array, dimension (2*N) — just the workspace, doing its little behind-the-scenes thing 🎀

INFO

INFO is INTEGER — the vibe check:

  • = 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 117 of file zhpcon.f.

🧚 Author 🧚

Generated automatically by Doxygen for LAPACK from the source code. Not me, not you — Doxygen ate that one 💅

okay that’s the whole page, bestie — footer tea: LAPACK Version 3.12.0, page SRC/zhpcon.f(3) 🦋💖✨

📦 where this page comes from