BLAS/SRC/csyrk.f(3)

💖 BLAS/SRC/csyrk.f 💖

okay bestie, sit DOWN, because this is one of the LAPACK BLAS pages (yes, from the LAPACK manual, the BLAS/SRC/csyrk.f one specifically) and it's genuinely so useful once it clicks. we're doing a rank-k update on a symmetric matrix, no cap. let's go ✨

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🌸 SYNOPSIS 🌸

Functions/Subroutines

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

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🎀 Function/Subroutine Documentation 🎀

subroutine csyrk (character uplo, character trans, integer n, integer k,
    complex alpha, complex, dimension(lda,*) a, integer lda, complex beta,
    complex, dimension(ldc,*) c, integer ldc)

CSYRK 💅

✨ Purpose ✨

CSYRK 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. it's giving "glow up your matrix in place" fr fr 🦋

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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.

• N

N is INTEGER. On entry, N specifies the order of the matrix C. N must be at least zero. ✨

• 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', K specifies the number of rows of the matrix A. K must be at least zero. 🫶

• ALPHA

ALPHA is COMPLEX. On entry, ALPHA specifies the scalar alpha.

• A

A is COMPLEX 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. 🌸

• 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 ). don't skip this one bestie, the compiler will Not be forgiving 😭

• BETA

BETA is COMPLEX. On entry, BETA specifies the scalar beta.

• C

C is COMPLEX 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.

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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.

Definition at line 166 of file csyrk.f.

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👑 Author 👑

Generated automatically by Doxygen for LAPACK from the source code.

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and that's the whole thing, bestie!! this page is Version 3.12.0, dated Tue Nov 28 2023 12:08:41, and it lives at BLAS/SRC/csyrk.f(3) — mwah, iconic, periodt 💖✨🎀