SRC/ssycon.f(3)

🎀 SRC/ssycon.f 🎀

okay bestie, welcome to the Library Functions Manual page for SRC/ssycon.f — it's giving LAPACK, it's giving condition-number math, and we're gonna get through it together. 💅✨

🌸 NAME 🌸

• SRC/ssycon.f

literally that's the name section, no cap. 🫶

✨ SYNOPSIS ✨

🦋 Functions/Subroutines 🦋

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

SSYCON — iconic routine name, obviously. 👑

💖 Function/Subroutine Documentation 💖

🌈 subroutine ssycon 🌈

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

SSYCON — here's the whole vibe.

🧚 Purpose 🧚

Bestie, focus: SSYCON estimates the reciprocal of the condition number (in the 1-norm) of a real symmetric matrix A using the factorization A = U*D*U**T or A = L*D*L**T computed by SSYTRF. 🦋

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 math, and yes it's important. 💅

🎀 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. 🌸
• A — A is REAL array, dimension (LDA,N). The block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by SSYTRF.
• 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 SSYTRF.
• 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 at line 128 of file ssycon.f.

🫶 Author 🫶

Generated automatically by Doxygen for LAPACK from the source code.

---

that's the whole page, bestie — footer says LAPACK Version 3.12.0 and source page SRC/ssycon.f(3). mwah 💜💅🎀