/home/abui...SRC/ssyr.f(3)

💖 SSYR 💖

ok so bestie, this is a page from the Library Functions Manual, and the file it lives in is literally:

/home/abui...SRC/ssyr.f(3)

and the NAME section is just the full build path, no cap:

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

like, that's the whole name. iconic of LAPACK honestly.

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✨ SYNOPSIS ✨

Functions/Subroutines

subroutine SSYR (uplo, n, alpha, x, incx, a, lda)

SSYR — that's it, that's the subroutine 🫶

🦋 Function/Subroutine Documentation 🦋

subroutine SSYR (character uplo, integer n, real alpha, real, dimension(*) x, integer incx, real, dimension(lda,*) a, integer lda)

SSYR

🎀 Purpose:

!>
!> SSYR   performs the symmetric rank 1 operation
!>
!>    A := alpha*x*x**T + A,
!>
!> where alpha is a real scalar, x is an n element vector and A is an
!> n by n symmetric matrix.
!>

so basically it takes your symmetric matrix A and adds a rank-1 update to it — alpha times x times x-transpose — and drops the result right back into A. main character behavior fr fr 💅

🌸 Parameters 🌸

• UPLO — CHARACTER*1. on entry, UPLO says whether we're messing with the upper or lower triangular part of the array A:
  • UPLO = 'U' or 'u' — only the upper triangular part of A is to be referenced.
  • UPLO = 'L' or 'l' — only the lower triangular part of A is to be referenced.
• N — INTEGER. on entry, N specifies the order of the matrix A. and N must be at least zero. minimum-effort queen, we respect it.
• ALPHA — REAL. on entry, ALPHA specifies the scalar alpha. that's the whole job.
• X — REAL array, dimension at least ( 1 + ( n - 1 )*abs( INCX ) ). before entry, the incremented array X must contain the n element vector x. yes the whole thing, no shortcuts.
• INCX — INTEGER. on entry, INCX specifies the increment for the elements of X. INCX must not be zero. like seriously, do not. 🚫
• A — REAL array, dimension ( LDA, N ). okay buckle up:
  • before entry with UPLO = 'U' or 'u', the leading n by n upper triangular part of the array A must contain the upper triangular part of the symmetric matrix, and the strictly lower triangular part of A is not referenced. on exit, the upper triangular part of the array A is overwritten by the upper triangular part of the updated matrix.
  • before entry with UPLO = 'L' or 'l', the leading n by n lower triangular part of the array A must contain the lower triangular part of the symmetric matrix, and the strictly upper triangular part of A is not referenced. on exit, the lower triangular part of the array A is overwritten by the lower triangular part of the updated matrix.
• LDA — INTEGER. on entry, LDA specifies the first dimension of A as declared in the calling (sub) program. LDA must be at least max( 1, n ). gotta leave room, bestie.

👑 Author

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

💜 Further Details:

!>
!>  Level 2 Blas routine.
!>
!>  -- Written on 22-October-1986.
!>     Jack Dongarra, Argonne National Lab.
!>     Jeremy Du Croz, Nag Central Office.
!>     Sven Hammarling, Nag Central Office.
!>     Richard Hanson, Sandia National Labs.
!>

a Level 2 BLAS routine, written on 22-October-1986 — the OGs really said "we'll handle it" and then handled it. 🙏

Definition at line 131 of file ssyr.f.

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💫 Author

Generated automatically by Doxygen for LAPACK from the source code. not a human, just vibes and a parser 🧚

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k that's the whole page!! no extra lore, everything's up there ⭐

LAPACK · Version 3.12.0 · /home/abui...SRC/ssyr.f(3) — mwah, go forth and symmetrize 💅💖🎀