SRC/sspcon.f(3)

Hey bestie, welcome to the Library Functions Manual page for SRC/sspcon.f — yes, it’s giving real symmetric packed matrices and condition numbers, and honestly it ate. 💅

🌸 NAME 🌸

SRC/sspcon.f — that’s the page title, bestie. That’s the whole NAME section. Iconic minimalism.

✨ SYNOPSIS ✨

🦋 Functions/Subroutines 🦋

• subroutine sspcon (uplo, n, ap, ipiv, anorm, rcond, work, iwork, info) — SSPCON

🧚 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

💖 Purpose 💖

Okay so SSPCON estimates the reciprocal of the condition number — that’s the 1-norm one — 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))). Periodt. ✨

🎀 Parameters 🎀

• UPLO — 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 — INTEGER. The order of the matrix A. N >= 0.
• AP — REAL array, dimension (N*(N+1)/2). 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 — INTEGER array, dimension (N). Details of the interchanges and the block structure of D as determined by SSPTRF.
• ANORM — REAL. The 1-norm of the original matrix A.
• RCOND — 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 — REAL array, dimension (2*N).
• IWORK — INTEGER array, dimension (N).
• INFO — 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 sspcon.f.

🧚 Author — generated-page edition 🧚

Generated automatically by Doxygen for LAPACK from the source code.

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Okay bye bestie — footer vibe check: LAPACK, Version 3.12.0, SRC/sspcon.f(3). Mwah 💋