BLAS/SRC/dsyrk.f(3)

✨ BLAS/SRC/dsyrk.f ✨

okay bestie, welcome to the LAPACK manual page for BLAS/SRC/dsyrk.f 💖 this is the BLAS girlies' symmetric rank-k update, and she is that girl. let's get into it 🫶

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🌸 SYNOPSIS 🌸

Functions/Subroutines

• subroutine dsyrk (uplo, trans, n, k, alpha, a, lda, beta, c, ldc) — DSYRK

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💜 Function/Subroutine Documentation 💜

subroutine dsyrk (character uplo, character trans, integer n, integer k, double precision alpha, double precision, dimension(lda,) *a, integer lda, double precision beta, double precision, dimension(ldc,) *c, integer ldc)

DSYRK — she's the main character fr fr 👑

🎀 Purpose 🎀

okay so DSYRK performs one of the symmetric rank k operations:

C := alpha*A*A**T + beta*C,

or

C := alpha*A**T*A + beta*C,

where alpha and beta are scalars, C is an n by n symmetric matrix, and A is an n by k matrix in the first case and a k by n matrix in the second case. literally that's the whole vibe ✨

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💅 Parameters 💅

• UPLO — UPLO is CHARACTER*1. On entry, UPLO specifies whether the upper or lower triangular part of the array C is to be referenced, as follows:
  • UPLO = 'U' or 'u' — Only the upper triangular part of C is to be referenced.
  • UPLO = 'L' or 'l' — Only the lower triangular part of C is to be referenced.
• TRANS — TRANS is CHARACTER*1. On entry, TRANS specifies the operation to be performed, as follows:
  • TRANS = 'N' or 'n' — C := alpha*A*A**T + beta*C.
  • TRANS = 'T' or 't' — C := alpha*A**T*A + beta*C.
  • TRANS = 'C' or 'c' — C := alpha*A**T*A + beta*C.
• N — N is INTEGER. On entry, N specifies the order of the matrix C. N must be at least zero. no negative energy allowed 🙅‍♀️
• K — K is INTEGER. On entry with TRANS = 'N' or 'n', K specifies the number of columns of the matrix A, and on entry with TRANS = 'T' or 't' or 'C' or 'c', K specifies the number of rows of the matrix A. K must be at least zero. again, zero is the floor, we do not go below 💀
• ALPHA — ALPHA is DOUBLE PRECISION. On entry, ALPHA specifies the scalar alpha.
• A — A is DOUBLE PRECISION array, dimension ( LDA, ka ), where ka is k when TRANS = 'N' or 'n', and is n otherwise. Before entry with TRANS = 'N' or 'n', the leading n by k part of the array A must contain the matrix A; otherwise the leading k by n part of the array A must contain the matrix A. she's flexible like that 💁‍♀️
• LDA — LDA is INTEGER. On entry, LDA specifies the first dimension of A as declared in the calling (sub) program. When TRANS = 'N' or 'n' then LDA must be at least max( 1, n ), otherwise LDA must be at least max( 1, k ).
• BETA — BETA is DOUBLE PRECISION. On entry, BETA specifies the scalar beta.
• C — C is DOUBLE PRECISION array, dimension ( LDC, N ).
  • Before entry with UPLO = 'U' or 'u', the leading n by n upper triangular part of the array C must contain the upper triangular part of the symmetric matrix, and the strictly lower triangular part of C is not referenced. On exit, the upper triangular part of the array C 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 C must contain the lower triangular part of the symmetric matrix, and the strictly upper triangular part of C is not referenced. On exit, the lower triangular part of the array C is overwritten by the lower triangular part of the updated matrix.
• LDC — LDC is INTEGER. On entry, LDC specifies the first dimension of C as declared in the calling (sub) program. LDC must be at least max( 1, n ).

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👑 Author 👑

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

the academic royalty that brought her into existence, we stan 🫶

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🦋 Further Details 🦋

Level 3 Blas routine.

-- Written on 8-February-1989.
   Jack Dongarra, Argonne National Laboratory.
   Iain Duff, AERE Harwell.
   Jeremy Du Croz, Numerical Algorithms Group Ltd.
   Sven Hammarling, Numerical Algorithms Group Ltd.

1989?? and she's still serving, periodt 💅 iconic behavior only.

Definition at line 168 of file dsyrk.f.

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⭐ Author (page-level) ⭐

Generated automatically by Doxygen for LAPACK from the source code. not me being auto-generated, i'm literally built different 🤖✨

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Version 3.12.0 — Tue Nov 28 2023 12:08:41 — BLAS/SRC/dsyrk.f(3)

k bye bestie, go forth and update your symmetric matrices 💖🌸🎀🦋✨