ZSPCON(3)

💖 ZSPCON(3) 💖

okay so bestie, welcome to the zspcon.f(3) page from the Library Functions Manual — manual name folded in near the top like a little name tag, no cap. This is all about the ZSPCON subroutine, and yes it’s giving LAPACK condition-number math. ✨

🌸 NAME 🌸

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

That’s the path, periodt. 🫶

✨ SYNOPSIS ✨

Functions/Subroutines energy:

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

🦋 Function/Subroutine Documentation 🦋

Full signature, character-for-character:

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

🌟 Purpose 🌟

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

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

🎀 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 — COMPLEX*16 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 ZSPTRF, stored as a packed triangular matrix.
• IPIV — INTEGER array, dimension (N). Details of the interchanges and the block structure of D as determined by ZSPTRF.
• ANORM — DOUBLE PRECISION. The 1-norm of the original matrix A.
• RCOND — 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.
• WORK — COMPLEX*16 array, dimension (2*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 117 of file zspcon.f.

🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code.

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okay that’s the whole page, bestie! Footer-flavored sign-off: LAPACK Version 3.12.0, page path /home/abui...RC/zspcon.f(3). No date line was in the footer I got, so no invented date — periodt. 💅✨🫶