SSPCON(3)

sspcon.f(3) — Library Functions Manual 💅✨

okay bestie, this is the manual page for /home/abui...RC/sspcon.f(3) — yes, the manual name is folded right in, and we are about to give SSPCON the full main-character treatment. no cap. 🫶

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🎀 NAME 🎀

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

That is literally the NAME section, bestie — it’s the whole path, and we are keeping it exactly like that. iconic. ✨

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🌸 SYNOPSIS 🌸

Functions/Subroutines

Functions/Subroutines
    subroutine SSPCON (uplo, n, ap, ipiv, anorm, rcond, work, iwork, info)
        SSPCON

So yes, the synopsis lists subroutine SSPCON (uplo, n, ap, ipiv, anorm, rcond, work, iwork, info), and then it says SSPCON again. We are not merging that, not deleting it, not “fixing” it — it stays. periodt. 💅

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💖 Function/Subroutine Documentation 💖

subroutine SSPCON (character uplo, integer n, real, dimension( * ) ap,
    integer, dimension( * ) ipiv, real anorm, real rcond, real, dimension( *
    ) work, integer, dimension( * ) iwork, integer info)

SSPCON — the subroutine herself. 👑

🎯 Purpose 🎯

SSPCON estimates the reciprocal of the condition number (in the 1-norm) of a real symmetric packed matrix A using the factorization A = U*D*U**T or A = L*D*L**T computed by SSPTRF.

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: estimate the inverse norm, then flip it into a reciprocal condition number. 🦋

🧾 Parameters 🧾

• UPLO — UPLO is CHARACTER*1. It 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 — N is INTEGER. The order of the matrix A. N >= 0. simple as that, bestie. 🌟
• AP — AP is REAL array, dimension (N*(N+1)/2). This holds the block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by SSPTRF, stored as a packed triangular matrix.
• IPIV — IPIV is INTEGER array, dimension (N). Details of the interchanges and the block structure of D as determined by SSPTRF. the receipts from SSPTRF, basically. 🧾
• ANORM — ANORM is REAL. The 1-norm of the original matrix A.
• RCOND — 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 — WORK is REAL array, dimension (2*N).
• IWORK — IWORK is INTEGER array, dimension (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 🧵

Definition at line 123 of file sspcon.f.

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👑 Author 👑

Generated automatically by Doxygen for LAPACK from the source code.

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sign-off, bestie: LAPACK Version 3.12.0 and the footer path /home/abui...RC/sspcon.f(3) — that’s the source/version and page path; no separate date line is printed on this one. 💅🌈