SRC/dlauum.f(3)

💅 SRC/dlauum.f

okay so bestie, this is a page from the Library Functions Manual — page three of SRC/dlauum.f, and it's literally just one subroutine that's about to become your new obsession 🎀

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✨ SYNOPSIS ✨

Functions/Subroutines

• subroutine dlauum (uplo, n, a, lda, info) — DLAUUM computes the product UUH or LHL, where U and L are upper or lower triangular matrices (blocked algorithm). no cap, that's the whole vibe 💅

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🦋 Function/Subroutine Documentation 🦋

🔥 the subroutine itself

subroutine dlauum (character uplo, integer n, double precision, dimension(
    lda, * ) a, integer lda, integer info)

DLAUUM computes the product UUH or LHL, where U and L are upper or lower triangular matrices (blocked algorithm). she's giving main character energy fr fr 👑

🎯 Purpose

okay so picture this: DLAUUM computes the product U * U**T or L**T * L, where the triangular factor U or L is stored in the upper or lower triangular part of the array A.

the !> bits in the original are just Doxygen being extra — the facts are what matter, bestie 💖

• If UPLO = 'U' or 'u' then the upper triangle of the result is stored, overwriting the factor U in A. slay.
• If UPLO = 'L' or 'l' then the lower triangle of the result is stored, overwriting the factor L in A. also slay.

it's literally the blocked form of the algorithm, calling Level 3 BLAS — she's efficient like that ⚡

🌸 Parameters

• UPLO — UPLO is CHARACTER*1. Specifies whether the triangular factor stored in the array A is upper or lower triangular:
  • = 'U': Upper triangular 💜
  • = 'L': Lower triangular 🩷
• N — N is INTEGER. The order of the triangular factor U or L. N >= 0. (zero is valid, bestie, don't be weird about it)
• A — A is DOUBLE PRECISION array, dimension (LDA,N). On entry, the triangular factor U or L. On exit, if UPLO = 'U', the upper triangle of A is overwritten with the upper triangle of the product U * U**T; if UPLO = 'L', the lower triangle of A is overwritten with the lower triangle of the product L**T * L. she transform, okay? 🦋
• LDA — LDA is INTEGER. The leading dimension of the array A. LDA >= max(1,N). respect the max(1,N), it's not optional 😤
• INFO — INFO is INTEGER:
  • = 0: successful exit ✨
  • < 0: if INFO = -k, the k-th argument had an illegal value 💀

heads up: a negative INFO means an argument was illegal — that's the error path, so check it, bestie, don't just vibe past it 🙈

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👑 Author

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

the whole squad contributed, we love a collab 🌈

Definition at line 101 of file dlauum.f.

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🌟 Author (footer energy)

Generated automatically by Doxygen for LAPACK from the source code. not me being auto-generated by a doc tool 😭 iconic.

this masterpiece is LAPACK, Version 3.12.0, from SRC/dlauum.f(3) — periodt, go call dlauum, she's ready for you 💖✨🎀