TESTING/LIN/chet01.f(3)

okay bestie, this is the Library Functions Manual page for TESTING/LIN/chet01.f 💅 and it’s literally giving “Hermitian matrix reconstruction + residual check” energy. No cap.

✨ NAME ✨

• TESTING/LIN/chet01.f — that’s the name, that’s the vibe, periodt. 💖

🦋 SYNOPSIS 🦋

🌈 Functions/Subroutines 🌈

subroutine chet01 (uplo, n, a, lda, afac, ldafac, ipiv, c, ldc, rwork,
     resid)

CHET01

🎀 Function/Subroutine Documentation 🎀

Here’s the full signature, bestie, copied exactly so nobody loses a single character:

subroutine chet01 (character uplo, integer n, complex, dimension( lda, * )
     a, integer lda, complex, dimension( ldafac, * ) afac, integer ldafac,
     integer, dimension( * ) ipiv, complex, dimension( ldc, * ) c, integer
     ldc, real, dimension( * ) rwork, real resid)

CHET01

🎯 Purpose 🎯

okay so CHET01 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. That’s the whole assignment, and it ate. 🔥

💅 Parameters 💅

Every single one, no skips:

• UPLO — UPLO is CHARACTER*1. It 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 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 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 CHETRF.
• 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 CHETRF.
• C — C is COMPLEX array, dimension (LDC,N).
• LDC — LDC is INTEGER. The leading dimension of the array C. LDC >= max(1,N).
• RWORK — RWORK is REAL array, dimension (N).
• RESID — RESID is REAL. If UPLO = 'L', norm(L*D*L' - A) / ( N * norm(A) * EPS ). If UPLO = 'U', norm(U*D*U' - A) / ( N * norm(A) * EPS ).

👑 Author 👑

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

🧭 Definition at line 🧭

Definition at line 124 of file chet01.f.

💌 Author (the Doxygen one) 💌

Generated automatically by Doxygen for LAPACK from the source code.

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okay that’s the whole page, bestie 🫶 source/version check: this is LAPACK Version 3.12.0 for TESTING/LIN/chet01.f(3). The footer doesn’t give a separate date, so I’m not making one up 😌💅. Slay your Hermitian residuals and bye ✨