BLAS/SRC/dsyr2.f(3)

💖 BLAS/SRC/dsyr2.f(3) — bestie we're doing LAPACK today 💖

okay so like, this page lives in the LAPACK manual (yes the whole BLAS/SRC/dsyr2.f situation) and it's literally just one little subroutine that's been carrying linear algebra on its back since the 80s. no big deal. 🎀

---

✨ NAME ✨

BLAS/SRC/dsyr2.f — the file itself, the moment, the icon. 💅

---

🌸 SYNOPSIS 🌸

Functions/Subroutines

subroutine dsyr2 (uplo, n, alpha, x, incx, y, incy, a, lda)

DSYR2 — that's the name, that's the vibe.

---

🦋 Function/Subroutine Documentation 🦋

subroutine dsyr2

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:

DSYR2 performs the symmetric rank 2 operation

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. periodt. 💖

⭐ Parameters

• UPLO — CHARACTER*1. On entry, UPLO specifies whether the upper or lower triangular part of the array A is to be referenced as follows:
  • 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. N must be at least zero.
• ALPHA — DOUBLE PRECISION. On entry, ALPHA specifies the scalar alpha.
• X — 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 — INTEGER. On entry, INCX specifies the increment for the elements of X. INCX must not be zero. 🚫
• Y — 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 — INTEGER. On entry, INCY specifies the increment for the elements of Y. INCY must not be zero. 🚫
• A — 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 — 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 ).

---

👑 Author 👑

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

(an absolute supergroup of institutions, no cap 🫶)

---

💀 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.

the way these four legends wrote this on 22-October-1986 and it's still out here doing the most... main character energy fr fr 🌈

---

📍 Definition at line 146 of file dsyr2.f.

---

💜 Author 💜

Generated automatically by Doxygen for LAPACK from the source code. (not a human girlie, just a robot doing its thing 🤖✨)

---

okay bestie that's the whole page, you ate it, go call dsyr2 and be iconic 💅🍓

Version 3.12.0 · Tue Nov 28 2023 12:08:41 · BLAS/SRC/dsyr2.f(3) — mwah, bye 🎀💖🦋