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

👑 /home/abui...hetrs_aa.f(3) — Library Functions Manual energy ✨

okay so bestie, welcome to the glow-up zone 💅 this is a page from the Library Functions Manual, and it's literally the documentation for one very specific LAPACK file. buckle up, we're getting into it 🎀

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✨ NAME ✨

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

that's the whole name, no cap. it's giving "my full government name is a file path" 😭 but honestly? iconic.

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🦋 SYNOPSIS 🦋

Functions/Subroutines

subroutine CHETRS_AA (uplo, n, nrhs, a, lda, ipiv, b, ldb, work, lwork,
    info)

CHETRS_AA — that's her. that's the main character 👑

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🌸 Function/Subroutine Documentation 🌸

subroutine CHETRS_AA (character uplo, integer n, integer nrhs, complex,
    dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv,
    complex, dimension( ldb, * ) b, integer ldb, complex, dimension( * )
    work, integer lwork, integer info)

CHETRS_AA 💖 (the long-form signature, for when you need to see everything)

Purpose: 💫

!>
!> CHETRS_AA solves a system of linear equations A*X = B with a complex
!> hermitian matrix A using the factorization A = U**H*T*U or
!> A = L*T*L**H computed by CHETRF_AA.
!>

so basically she solves A*X = B for you when A is a complex hermitian matrix 🧚 and she does it using the factorization that CHETRF_AA already did the hard work of computing. teamwork, bestie 🫶

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💜 Parameters 💜

• UPLO — UPLO is CHARACTER*1. tells us whether the factorization details got stored as an upper or lower triangular matrix. the options are:
  • = 'U': upper triangular, form is A = U**H*T*U;
  • = 'L': lower triangular, form is A = L*T*L**H.
• N — N is INTEGER. the order of the matrix A. and the rule is N >= 0 🙅‍♀️ no negativity allowed.
• NRHS — NRHS is INTEGER. the number of right hand sides, i.e., the number of columns of the matrix B. constraint: NRHS >= 0 ✅
• A — A is COMPLEX array, dimension (LDA,N). this is where the details of the factors computed by CHETRF_AA live 🏠
• LDA — LDA is INTEGER. the leading dimension of the array A, and you must have LDA >= max(1,N) ⚠️ don't test her.
• IPIV — IPIV is INTEGER array, dimension (N). details of the interchanges as computed by CHETRF_AA 🔄
• B — B is COMPLEX array, dimension (LDB,NRHS). on entry: the right hand side matrix B. on exit: the solution matrix X. she really said "same array, new me" 💅✨
• LDB — LDB is INTEGER. the leading dimension of the array B. requirement: LDB >= max(1,N) 🚨
• WORK — WORK is COMPLEX array, dimension (MAX(1,LWORK)) 🛠️
• LWORK — LWORK is INTEGER. the dimension of the array WORK, and the rule is LWORK >= max(1,3*N-2) 📏 memorize it, iykyk.
• INFO — INFO is INTEGER. the vibe check at the end:
  • = 0: successful exit 🎉
  • < 0: if INFO = -i, the i-th argument had an illegal value 💀 (rude, but she's telling you which one)

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🎀 Author 🎀

the legends behind it:

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

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📖 Definition at line 129 of file chetrs_aa.f. 📖

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🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code. she didn't write herself, bestie — the robots did 🤖✨

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fr fr that's the whole page. every flag, every constraint, every author, all accounted for. periodt. 💅

LAPACK — Version 3.12.0 — and that footer date lives at /home/abui...hetrs_aa.f(3) 🦋🌸 mwah, go solve some linear systems 🫶🔥