CHET01(3)

💖 NAME 💖

okay bestie, you're reading CHET01(3) from the Library Functions Manual, and she is here to reconstruct a Hermitian indefinite matrix and check the residual 💅. The actual source file path is:

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/LIN/chet01.f

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✨ SYNOPSIS ✨

🧚 Functions/Subroutines 🧚

       subroutine CHET01 (uplo, n, a, lda, afac, ldafac, ipiv, c, ldc, rwork,
           resid)
           CHET01

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🦋 Function/Subroutine Documentation 🦋

   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 🎀

CHET01 reconstructs a Hermitian indefinite matrix A from its block L*D*L' or U*D*U' factorization, then 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. literally iconic math behaviour 💅✨

🌸 Parameters 🌸

• UPLO — UPLO is CHARACTER*1. It says which triangle of the Hermitian matrix A is stored: 'U' means upper triangular, and 'L' means lower triangular. Pick your lane, bestie 💖
• N — N is INTEGER. It's the number of rows and columns of the matrix A, and N >= 0. no negative-size nonsense, periodt 🫶
• A — A is COMPLEX array, dimension (LDA,N). This is the original Hermitian matrix A. main character matrix energy 👑
• LDA — LDA is INTEGER. It's the leading dimension of the array A, and LDA >= max(1,N). respect the leading dimension or perish 😭
• AFAC — AFAC is COMPLEX array, dimension (LDAFAC,N). This is 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. yes, she contains lore 🎀
• LDAFAC — LDAFAC is INTEGER. It's the leading dimension of the array AFAC, and LDAFAC >= max(1,N). get that leading dimension in check bestie 💅
• IPIV — IPIV is INTEGER array, dimension (N). These are the pivot indices from CHETRF. pivot era 🔥
• C — C is COMPLEX array, dimension (LDC,N). that's the reconstructed-matrix slot, no extra commentary needed 🦋
• LDC — LDC is INTEGER. It's the leading dimension of the array C, and LDC >= max(1,N). another leading dimension, another slay 🌈
• RWORK — RWORK is REAL array, dimension (N). real workspace, real vibes ✨
• RESID — RESID is REAL. If UPLO = 'L', it's norm(L*D*L' - A) / ( N * norm(A) * EPS ). If UPLO = 'U', it's norm(U*D*U' - A) / ( N * norm(A) * EPS ). this is the final boss residual check 😤

👑 Author 👑

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

Definition at line 124 of file chet01.f.

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🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code.

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bye bestie 💖 — this page is from LAPACK Version 3.12.0, and the footer path is /home/abui...IN/chet01.f(3). No date is listed in the footer, so consider this your timestamp-free sign-off 🎀💋