SRC/csycon.f(3)

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version 3.12.1 · 7 versions
, in arch rolling

✨ NAME ✨

SRC/csycon.f — that’s the page, bestie, and yes, we’re in the Library Functions Manual. Cute, concise, iconic. 💅

🦋 SYNOPSIS 🦋

Functions/Subroutines

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

CSYCON is the main character here. 👑

💖 Function/Subroutine Documentation 💖

🌸 subroutine csycon — CSYCON 🌸

subroutine csycon (character uplo, integer n, complex, dimension( lda, * )
a, integer lda, integer, dimension( * ) ipiv, real anorm, real rcond,
complex, dimension( * ) work, integer info)

CSYCON — say it with me, bestie. 💫

🎯 Purpose 🎯

CSYCON estimates the reciprocal of the condition number (in the 1-norm) of a complex symmetric matrix A using the factorization A = U*D*U**T or A = L*D*L**T computed by CSYTRF. Lowkey iconic. ✨

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. 💖

🧾 Parameters 🧾

  • 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**T;
    • = 'L': Lower triangular, form is A = L*D*L**T.
  • N — is INTEGER. The order of the matrix A. N >= 0.
  • A — is COMPLEX array, dimension (LDA,N). The block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by CSYTRF.
  • LDA — is INTEGER. The leading dimension of the array A. LDA >= max(1,N).
  • IPIV — is INTEGER array, dimension (N). Details of the interchanges and the block structure of D as determined by CSYTRF.
  • ANORM — is REAL. The 1-norm of the original matrix A.
  • RCOND — is REAL. 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 — is COMPLEX array, dimension (2*N).
  • INFO — is INTEGER.
    • = 0: successful exit
    • < 0: if INFO = -i, the i-th argument had an illegal value
Bestie warning: INFO < 0 is not a vibe — 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 csycon.f.

🌈 Author 🌈

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✨ That’s the whole page, bestie! Source: SRC/csycon.f(3); version: LAPACK Version 3.12.0. The footer didn’t give me a date, so I’m not inventing one — periodt. 💖

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