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

💅 DSYR — NAME 🌸

ok so bestie, this whole page is literally about /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/BLAS/SRC/dsyr.f — that's the file, that's the name, we're not being mysterious about it 💖 (and yeah, the header of this manpage is /home/abui...SRC/dsyr.f(3) from the Library Functions Manual, in case you were wondering where you even are).

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✨ SYNOPSIS ✨

🎀 Functions/Subroutines

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

DSYR 🫶 (yes that's the whole description, it's giving "just read the page below")

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🦋 Function/Subroutine Documentation 🦋

subroutine DSYR (character uplo, integer n, double precision alpha,
    double precision, dimension(*) x, integer incx,
    double precision, dimension(lda,*) a, integer lda)

DSYR 👑 — again, that's the name, but like, keep reading because this is the good part.

⭐ Purpose:

!>
!> DSYR   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 does a symmetric rank 1 update — A := alpha*x*x**T + A — and that's it, that's the whole serve. no cap. 🔥

🌈 Parameters

• UPLO — is CHARACTER*1. on entry, UPLO tells us which triangular part of the array A we're referencing, like:
  • UPLO = 'U' or 'u' → only the upper triangular part of A is to be referenced, periodt.
  • UPLO = 'L' or 'l' → only the lower triangular part of A is to be referenced, that's the vibe.
• N — is INTEGER. on entry, N specifies the order of the matrix A. and N must be at least zero, no negativity allowed bestie 🙈
• ALPHA — is DOUBLE PRECISION. on entry, ALPHA specifies the scalar alpha. that's the whole job ok 💅
• X — is DOUBLE PRECISION array, dimension at least ( 1 + ( n - 1 )*abs( INCX ) ). before entry, the incremented array X must contain the n element vector x. literally must. 🍓
• INCX — is INTEGER. on entry, INCX specifies the increment for the elements of X. and INCX must not be zero 😭 like fr fr, don't do that.
• A — is DOUBLE PRECISION array, dimension ( LDA, N ). here's the tea:
  • 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 — is 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 ). that's the rule, don't argue with me 💀

🧚 Author

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

look at this absolute squad 👑 academia said "we all made this" and honestly? iconic.

🌸 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.
!>

so it's a Level 2 Blas routine, written on 22-October-1986 by Jack Dongarra (Argonne National Lab), Jeremy Du Croz (Nag Central Office), Sven Hammarling (Nag Central Office), and Richard Hanson (Sandia National Labs). 1986!! these legends were doing this before most of us existed 😭 the foresight is unmatched.

Definition at line 131 of file dsyr.f. that's the receipts, go look 💖

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💜 Author

Generated automatically by Doxygen for LAPACK from the source code. so like... the robots wrote this part, not me 🤖✨ respect.

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and that's the page bestie! 🫶 this came to you from LAPACK, Version 3.12.0, live and direct from /home/abui...SRC/dsyr.f(3) — mwah, go update some symmetric matrices 💅🌈⭐