DSYR2(3)

💖 DSYR2 💖

okay bestie, welcome to the DSYR2 page from the LAPACK Library Functions Manual — it lives at /home/abui...SRC/dsyr2.f(3) and it's giving very specific BLAS energy. no cap, every detail is staying right here. 💅

✨ NAME ✨

• /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/BLAS/SRC/dsyr2.f

like, that's the file path this whole page is about. periodt. 🎀

🦋 SYNOPSIS 🦋

🌸 Functions/Subroutines 🌸

subroutine DSYR2 (uplo, n, alpha, x, incx, y, incy, a, lda)
    DSYR2

💖 Function/Subroutine Documentation 💖

🧚 subroutine DSYR2 🧚

here's the exact signature, bestie — do not lose a single character:

subroutine DSYR2 (character uplo, integer n, double precision alpha, double
    precision, dimension(*) x, integer incx, double precision, dimension(*)
    y, integer incy, double precision, dimension(lda,*) a, integer lda)
    DSYR2

🎀 Purpose 🎀

okay so DSYR2 performs the symmetric rank 2 operation. the main-character formula is literally:

A := alpha*x*y**T + alpha*y*x**T + A,

where alpha is a scalar, x and y are n element vectors, and A is an n by n symmetric matrix. iconic math behavior. ✨

💅 Parameters 💅

• UPLO — is CHARACTER*1. on entry, UPLO tells you whether the upper or lower triangular part of the array A is to be referenced, like so:
  • 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 — is INTEGER. on entry, N specifies the order of the matrix A. N must be at least zero. no negative nonsense, bestie. 🫶
• ALPHA — is DOUBLE PRECISION. on entry, ALPHA specifies the scalar alpha.
• 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.
• INCX — is INTEGER. on entry, INCX specifies the increment for the elements of X. INCX must not be zero. 🚨
• Y — is DOUBLE PRECISION array, dimension at least ( 1 + ( n - 1 )*abs( INCY ) ). before entry, the incremented array Y must contain the n element vector y.
• INCY — is INTEGER. on entry, INCY specifies the increment for the elements of Y. INCY must not be zero. same energy as INCX, fr fr. 🚨
• A — is DOUBLE PRECISION array, dimension ( LDA, N ).
  • 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 ). slay. 👑

👑 Author 👑

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

🧚 Further Details 🧚

the receipts say:

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.

Definition at line 146 of file dsyr2.f. 📍

⭐ Author ⭐

Generated automatically by Doxygen for LAPACK from the source code. yes, the robots did this one. 🤖✨

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okay that's the whole page, bestie 💅 — final footer vibes: LAPACK Version 3.12.0, page path /home/abui...SRC/dsyr2.f(3), and it was generated automatically by Doxygen for LAPACK from the source code. mwah 🫶💖