DLAUUM(3)

💅 NAME 💅

So bestie, this page is literally the manual for a single file, and the file's whole government name is:

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

Yes she's from the LAPACK Library Functions Manual, yes she's that girl. Buckle up 🎀

---

✨ 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).

---

🦋 Function/Subroutine Documentation 🦋

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

Okay so real talk, here's what she does: DLAUUM computes the product UUH or LHL, where U and L are upper or lower triangular matrices (blocked algorithm). That's the whole vibe.

🌸 Purpose 🌸

!> !> 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. !> !> If UPLO = 'U' or 'u' then the upper triangle of the result is stored, !> overwriting the factor U in A. !> If UPLO = 'L' or 'l' then the lower triangle of the result is stored, !> overwriting the factor L in A. !> !> This is the blocked form of the algorithm, calling Level 3 BLAS. !>

Translation for the girlies: she squares things up 💖 — takes the triangular factor U or L sitting in the upper or lower triangle of A, multiplies it by its transpose (U * U**T or L**T * L), and drops the answer right back into A. Main character behavior: she does NOT need extra storage, she reuses what's already there. And she's the blocked version — the one that calls Level 3 BLAS, iykyk 🔥

🎀 Parameters 🎀

• UPLO — CHARACTER*1. Tells her whether the triangular factor chillin' in A is upper or lower triangular:
  • = 'U': Upper triangular
  • = 'L': Lower triangular
• N — INTEGER. The order of the triangular factor U or L. So like, N >= 0, no exceptions 👑
• A — DOUBLE PRECISION array, dimension (LDA,N). On the way in, this is the triangular factor U or L. On the way out:
  • if UPLO = 'U', the upper triangle of A gets overwritten with the upper triangle of the product U * U**T;
  • if UPLO = 'L', the lower triangle of A gets overwritten with the lower triangle of the product L**T * L.

She ate and left no crumbs, but she also left no original data behind — that's the deal 🙈

• LDA — INTEGER. The leading dimension of the array A. Must be LDA >= max(1,N). Don't try her 💅
• INFO — INTEGER. The vibe check:
  • = 0: successful exit ✨
  • < 0: if INFO = -k, the k-th argument had an illegal value — so if something's off, she's telling you exactly which argument fumbled it 😭

---

👑 Author 👑

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

Definition at line 101 of file dlauum.f.

---

⭐ Author ⭐

Generated automatically by Doxygen for LAPACK from the source code. (Not a human, just robot slay 🫶)

---

Okay that's the whole page bestie, go forth and compute 🦋

LAPACK — Version 3.12.0 — dated /home/abui...RC/dlauum.f(3) 💜