ZLAUUM(3)

💅 zlauum.f(3) — the LAPACK library functions manual, bestie edition

okay so before we even start: this page lives at /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/zlauum.f and it's part of the LAPACK library functions manual. that's the whole vibe. 💖

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✨ NAME

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

like, that's literally the name. it's a path. she's a file path and she's iconic for it. 🎀

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🦋 SYNOPSIS

Functions/Subroutines

subroutine ZLAUUM (uplo, n, a, lda, info)

ZLAUUM computes the product UUH or LHL, where U and L are upper or lower triangular matrices (blocked algorithm).

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🌸 Function/Subroutine Documentation

subroutine ZLAUUM (character uplo, integer n, complex*16, dimension( lda, * ) a, integer lda, integer info)

ZLAUUM computes the product UUH or LHL, where U and L are upper or lower triangular matrices (blocked algorithm).

🌈 Purpose:

!>
!> ZLAUUM computes the product U * U**H or L**H * 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.
!>

so basically: give her a triangular factor chilling in A, and she'll hand you back U * U**H or L**H * L — and she does it in place, bestie. overwriting. no extra storage, no drama. and it's the blocked form, which means it calls Level 3 BLAS — that's the fast one. main character energy fr fr. 🔥

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👑 Parameters

• UPLO — UPLO is CHARACTER*1. tells her whether the triangular factor sitting in A is upper or lower:
  • = 'U': Upper triangular ⬆️
  • = 'L': Lower triangular ⬇️
• N — N is INTEGER. the order of the triangular factor U or L. and N >= 0, no cap (well, no negative cap, that's the rule 🫶).
• A — A is COMPLEX*16 array, dimension (LDA,N). on entry, it's 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**H;
  • if UPLO = 'L', the lower triangle of A is overwritten with the lower triangle of the product L**H * L.

she eats the input and leaves you the product in the same spot. slay. 💅

• LDA — LDA is INTEGER. the leading dimension of the array A. must be LDA >= max(1,N). respect the constraint or she'll be upset 🙈.
• INFO — INFO is INTEGER, the receipts:
  • = 0: successful exit ✨
  • < 0: if INFO = -k, the k-th argument had an illegal value 💀

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🧚 Author

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

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Definition at line 101 of file zlauum.f.

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⭐ Author

Generated automatically by Doxygen for LAPACK from the source code.

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okay and that's the tea 🍓 — this page is LAPACK, Version 3.12.0, and it's just /home/abui...RC/zlauum.f(3) doing her little thing. go call ZLAUUM, tell her I said hi, and remember: N >= 0, LDA >= max(1,N), and always check your INFO. mwah 💜🦋