/home/abui...N/zlaghe.f(3)

📦 version 3.12.0, in opensuse-leap 16.0

💅 NAME 💅

okay so bestie, this is the manual page for /home/abui...N/zlaghe.f(3) — like, from the Library Functions Manual, and the actual file lives at /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/MATGEN/zlaghe.f. yes that's a whole entire path, she's long, she's iconic, she's built different 🎀

nsg what she does? she makes you a hermitian matrix out of vibes and a random unitary. slay.

✨ SYNOPSIS ✨

Functions/Subroutines

subroutine ZLAGHE (n, k, d, a, lda, iseed, work, info)

ZLAGHE — that's her, that's the moment, that's the whole function 💅

🦋 Function/Subroutine Documentation 🦋

subroutine ZLAGHE (integer n, integer k, double precision, dimension( * ) d,
    complex*16, dimension( lda, * ) a, integer lda, integer, dimension( 4 )
    iseed, complex*16, dimension( * ) work, integer info)

ZLAGHE 👑

🎀 Purpose 🎀

!> !> ZLAGHE generates a complex hermitian matrix A, by pre- and post- !> multiplying a real diagonal matrix D with a random unitary matrix: !> A = U*D*U'. The semi-bandwidth may then be reduced to k by additional !> unitary transformations. !>

like literally she's out here taking your real diagonal D, sandwiching it between a random unitary matrix U and its conjugate transpose — A = U*D*U' — and boom, complex hermitian matrix, no cap 💖 and then if you want, the semi-bandwidth can get squished down to k with some extra unitary transformations. the way that works?? obsessed.

🌸 Parameters 🌸

  • N — N is INTEGER. it's the order of the matrix A, like how big she is. N >= 0 fr fr.
  • K — K is INTEGER. the number of nonzero subdiagonals within the band of A. so 0 <= K <= N-1, no wiggle room bestie, the range check is real.
  • D — D is DOUBLE PRECISION array, dimension (N). these are the diagonal elements of the diagonal matrix D. your main characters, your diagonal girlies 💜
  • A — A is COMPLEX*16 array, dimension (LDA,N). the generated n by n hermitian matrix A — and yes, the full matrix is stored, she's not hiding half of herself, transparency queen ✨
  • LDA — LDA is INTEGER. the leading dimension of the array A. must be LDA >= N, periodt.
  • ISEED — ISEED is INTEGER array, dimension (4). on entry, this is the seed of the random number generator — and listen, the rules are strict: the array elements must be between 0 and 4095, and ISEED(4) must be odd. on exit, the seed is updated (she evolves, she grows 💫).
  • WORK — WORK is COMPLEX*16 array, dimension (2*N). scratch space. do not perceive her. 🙈
  • INFO — INFO is INTEGER. exit status time:
    • = 0: successful exit, we ate, no crumbs 🍓
    • < 0: if INFO = -i, the i-th argument had an illegal value. so like, go check argument number i, bestie, that one's the problem 😭

👑 Author 👑

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

Definition at line 101 of file zlaghe.f. 🧚

⭐ Author ⭐

Generated automatically by Doxygen for LAPACK from the source code. (she didn't write her own bio, the robots did it for her, and honestly? respecting the automation 🙏)

💀 real talk though: ISEED(4) must be odd and every element must be in 0–4095. ignore that and it's giving illegal value, INFO < 0, and the whole vibe check fails. you've been warned 🫶

and that's the page!! sign-off time: this was LAPACK Version 3.12.0, page /home/abui...N/zlaghe.f(3) — go forth and generate hermitian matrices, mwah 💖🌈⭐

📦 where this page comes from