ZHET01(3)

okay so bestie, this is the glow-up of zhet01.f(3) 💅 — manual name zhet01.f(3), and it lives in the Library Functions Manual. The header path (yep, both header spots) is /home/abui...IN/zhet01.f(3). Buckle up, because this page is lowkey all about Hermitian matrix reconstruction. 🦋

🎀 NAME 🎀

The NAME is literally this file path, no cap:

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/LIN/zhet01.f

✨ SYNOPSIS ✨

Functions/Subroutines

Here’s the call signature, bestie — copy it exactly:

subroutine ZHET01 (uplo, n, a, lda, afac, ldafac, ipiv, c, ldc, rwork,
    resid)
    ZHET01

🫶 Function/Subroutine Documentation 🫶

ZHET01 (the subroutine herself, main character energy)

subroutine ZHET01 (character uplo, integer n, complex*16, dimension( lda, *
    ) a, integer lda, complex*16, dimension( ldafac, * ) afac, integer
    ldafac, integer, dimension( * ) ipiv, complex*16, dimension( ldc, * ) c,
    integer ldc, double precision, dimension( * ) rwork, double precision
    resid)
    ZHET01

Purpose

Okay so the raw Doxygen has !> sprinkled at the start of these comment lines (iykyk), but the actual purpose is this: ZHET01 reconstructs a Hermitian indefinite matrix A from its block L*D*L' or U*D*U' factorization and computes the residual

norm( C - A ) / ( N * norm(A) * EPS ),

where C is the reconstructed matrix, EPS is the machine epsilon, L' is the conjugate transpose of L, and U' is the conjugate transpose of U. slay. ✨

Parameters

Every parameter, every type, every dimension — here we go, no skipping:

• UPLO — UPLO is CHARACTER*1. Specifies whether the upper or lower triangular part of the Hermitian matrix A is stored:
  • = 'U': Upper triangular
  • = 'L': Lower triangular
• N — N is INTEGER. The number of rows and columns of the matrix A. N >= 0.
• A — A is COMPLEX*16 array, dimension (LDA,N). The original Hermitian matrix A.
• LDA — LDA is INTEGER. The leading dimension of the array A. LDA >= max(1,N).
• AFAC — AFAC is COMPLEX*16 array, dimension (LDAFAC,N). The factored form of the matrix A. AFAC contains the block diagonal matrix D and the multipliers used to obtain the factor L or U from the block L*D*L' or U*D*U' factorization as computed by ZHETRF.
• LDAFAC — LDAFAC is INTEGER. The leading dimension of the array AFAC. LDAFAC >= max(1,N).
• IPIV — IPIV is INTEGER array, dimension (N). The pivot indices from ZHETRF.
• C — C is COMPLEX*16 array, dimension (LDC,N). That’s the reconstructed matrix vibe.
• LDC — LDC is INTEGER. The leading dimension of the array C. LDC >= max(1,N).
• RWORK — RWORK is DOUBLE PRECISION array, dimension (N). Workspace, periodt.
• RESID — RESID is DOUBLE PRECISION. If UPLO = 'L', then norm(L*D*L' - A) / ( N * norm(A) * EPS ). If UPLO = 'U', then norm(U*D*U' - A) / ( N * norm(A) * EPS ).

Author

These legends:

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

Definition

Definition at line 124 of file zhet01.f.

📝 Author 📝

Generated automatically by Doxygen for LAPACK from the source code.

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okay bye bestie 🫶 this page is from LAPACK Version 3.12.0, and the footer path is /home/abui...IN/zhet01.f(3). Stay reconstructed, stay Hermitian, and don’t forget the conjugate transpose. 💖🎀🦋