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

💅 NAME 💅

ok so bestie, this page is about /home/abui...N/slarge.f(3) — yes that's a whole path as a page title, we don't make the rules — and it lives in the Library Functions Manual (that's the manual name, mwah, folded in just for you 🫶).

The actual star of the show is SLARGE, a Fortran subroutine from the LAPACK testing/MATGEN era, full path:

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/MATGEN/slarge.f

like, that's the whole lore 😭 it's a testing matrix generator file and we're reading its manpage. iconic behavior honestly.

---

✨ SYNOPSIS ✨

Functions/Subroutines

• subroutine SLARGE (n, a, lda, iseed, work, info) — SLARGE 🌸

---

🦋 Function/Subroutine Documentation 🦋

subroutine SLARGE (integer n, real, dimension( lda, * ) a, integer lda,
    integer, dimension( 4 ) iseed, real, dimension( * ) work, integer info)

SLARGE 💖

🎀 Purpose

!> !> SLARGE pre- and post-multiplies a real general n by n matrix A !> with a random orthogonal matrix: A = U*D*U'. !>

ok so literally what it does: it takes your real general n by n matrix A and sandwiches it — pre- and post-multiplies — with a random orthogonal matrix. the vibe is A = U*D*U'. no cap, that's the whole personality. 💅

🌸 Parameters

• N

!>          N is INTEGER
!>          The order of the matrix A.  N >= 0.

it's the order of the matrix A, and it has to be N >= 0 or we simply don't vibe. ⭐

• A

!>          A is REAL array, dimension (LDA,N)
!>          On entry, the original n by n matrix A.
!>          On exit, A is overwritten by U*A*U' for some random
!>          orthogonal matrix U.

bestie, this one's REAL, dimension (LDA,N). on entry it's your original n by n matrix A. on exit?? it's overwritten by U*A*U' for some random orthogonal matrix U. so like. your matrix is gone. replaced. main character energy but make it destructive 🫠💀

• LDA

!>          LDA is INTEGER
!>          The leading dimension of the array A.  LDA >= N.

the leading dimension of the array A. it must be LDA >= N, periodt.

• ISEED

!>          ISEED is INTEGER array, dimension (4)
!>          On entry, the seed of the random number generator; the array
!>          elements must be between 0 and 4095, and ISEED(4) must be
!>          odd.
!>          On exit, the seed is updated.

INTEGER array, dimension (4). on entry it's the seed of the random number generator — and here's the vibe check: every element must be between 0 and 4095, and ISEED(4) must be odd. don't ask, just respect it 🙈. on exit, the seed is updated (she grows, she changes 💜).

• WORK

!>          WORK is REAL array, dimension (2*N)

REAL array, dimension (2*N). just a little scratch space, doing her thing ✨

• INFO

!>          INFO is INTEGER
!>          = 0: successful exit
!>          < 0: if INFO = -i, the i-th argument had an illegal value

INTEGER, and the tea is:

• = 0: successful exit 🎉
• < 0: if INFO = -i, the i-th argument had an illegal value 💀 (so check your args, bestie)

👑 Author

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

like, a whole squad wrote this. legends only. 🫶

Definition at line 86 of file slarge.f.

---

🧚 Author 🧚

Generated automatically by Doxygen for LAPACK from the source code. (not a human, not a girlie, just a doc generator doing her little robot dance 🤖✨)

---

🌈 Sign-off 🌈

so this whole page is from LAPACK, Version 3.12.0, and it's filed under /home/abui...N/slarge.f(3) — drink water, keep your ISEED(4) odd, and go forth and multiply your matrices by random orthogonal ones 💖🎀🦋⭐👑🍓