BLAS/SRC/csyrk.f(3)

💅 BLAS/SRC/csyrk.f 💅

okay bestie, welcome to the csyrk page — it's a Fortran source file living its best life in BLAS/SRC/, and the manual name up top is literally just BLAS/SRC/csyrk.f. that's it, that's the name, no cap. ✨

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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 ✨

ok so here's the whole vibe — 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. two flavors, one subroutine, we love a versatile icon 💖

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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, like so:
  • 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. (zero is fine bestie, we don't judge 🫶)
• 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 ).
• 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.

ngl the 1989 date is giving vintage legend energy 👑

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🍓 Definition 🍓

Definition at line 166 of file csyrk.f. (yes, the whole thing lives down there — go look, iykyk 🔥)

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🧚 Author 🧚

Generated automatically by Doxygen for LAPACK from the source code.

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and that's the page, bestie!! 🎀 ok final sign-off: this was LAPACK, Version 3.12.0, dated BLAS/SRC/csyrk.f(3) — slay, periodt 💅✨🦋