/home/abui...con_rook.f(3)

NAME 💖

Okay so bestie, this page is /home/abui...con_rook.f(3), from the Library Functions Manual, and the name it's filed under is literally this path: /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/dsycon_rook.f.

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SYNOPSIS 🎀

Functions/Subroutines ✨

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

DSYCON_ROOK is the main character here 💅

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Function/Subroutine Documentation 🦋

The full signature, exactly as it is, no edits, no cap:

   subroutine DSYCON_ROOK (character uplo, integer n, double precision,
       dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv, double
       precision anorm, double precision rcond, double precision, dimension( *
       ) work, integer, dimension( * ) iwork, integer info)

And the routine is DSYCON_ROOK, periodt.

Purpose 🌸

DSYCON_ROOK 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 DSYTRF_ROOK.

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

it's giving condition-number math but make it LAPACK 💜

Parameters 👑

• UPLO — 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 — N is INTEGER. The order of the matrix A. N >= 0.
• A — A is DOUBLE PRECISION array, dimension (LDA,N). The block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by DSYTRF_ROOK.
• 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 DSYTRF_ROOK.
• ANORM — ANORM is DOUBLE PRECISION. The 1-norm of the original matrix A.
• RCOND — RCOND is 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 — WORK is DOUBLE PRECISION 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.

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Author 👑

The credited legends:

• Univ. of Tennessee
• Univ. of California Berkeley
• Univ. of Colorado Denver
• NAG Ltd.

Contributors 🫶

• April 2012, Igor Kozachenko, Computer Science Division, University of California, Berkeley
• September 2007, Sven Hammarling, Nicholas J. Higham, Craig Lucas, School of Mathematics, University of Manchester

Definition at line 142 of file dsycon_rook.f.

Author 🤖 (auto-generated)

Generated automatically by Doxygen for LAPACK from the source code.

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muah 💋 — this footer tea is LAPACK Version 3.12.0, file /home/abui...con_rook.f(3). That's the whole vibe, no notes 🎀