CSYR(3)

🦋 CSYR(3) — Library Functions Manual 💅

ok so bestie, welcome to the manual page for /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/csyr.f — yes that's the whole path, she's got a long name, we don't judge. This is the Library Functions Manual entry for CSYR, and I promise she's way less scary than that filename looks. 🎀

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✨ SYNOPSIS ✨

Functions/Subroutines

subroutine CSYR (uplo, n, alpha, x, incx, a, lda)

CSYR performs the symmetric rank-1 update of a complex symmetric matrix. that's it, that's the vibe 💖

🌸 Function/Subroutine Documentation 🌸

subroutine CSYR (character uplo, integer n, complex alpha, complex, dimension( * ) x, integer incx, complex, dimension( lda, * ) a, integer lda)

CSYR performs the symmetric rank-1 update of a complex symmetric matrix — same thing as above, just with the full glow-up of a signature 🫶

🧚 Purpose

ok so what she actually does:

A := alpha*x*x**H + A,

where alpha is a complex scalar, x is an n element vector and A is an n by n symmetric matrix. lowkey iconic, a whole rank 1 operation in one call ✨

💅 Parameters

• UPLO — UPLO is CHARACTER*1. on entry, UPLO says which triangular part of the array A we're referencing, like this:
  • 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.

unchanged on exit. periodt.

• N — N is INTEGER. on entry, N specifies the order of the matrix A. N must be at least zero. unchanged on exit.
• ALPHA — ALPHA is COMPLEX. on entry, ALPHA specifies the scalar alpha. unchanged on exit.
• X — X is COMPLEX array, dimension at least

( 1 + ( N - 1 )*abs( INCX ) )

before entry, the incremented array X must contain the N-element vector x. unchanged on exit. bestie the increment math is real, don't skip it 🙈

• INCX — INCX is INTEGER. on entry, INCX specifies the increment for the elements of X. INCX must not be zero. unchanged on exit. and like… genuinely do not pass zero, that's not a cute look 💀
• A — A is COMPLEX 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.

she gives you back the updated triangle, the other one is not her business 🦋

• LDA — 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 )

unchanged on exit.

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👑 Author

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

fr fr the whole squad showed up for this one 🫶

Definition at line 134 of file csyr.f. iykyk ⭐

🌈 Author

Generated automatically by Doxygen for LAPACK from the source code. yes, a robot wrote this and we're thanking her for her service 🤖💜

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and that's the tea, bestie — this page came from LAPACK, Version 3.12.0, and it lives at /home/abui.../SRC/csyr.f(3). go forth and rank-1 update responsibly ✨🎀💖