/home/abui...RC/csymv.f(3)

💖 NAME 💖

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/csymv.f — bestie, this whole page lives under the Library Functions Manual umbrella and it's literally just one Fortran file's whole personality. 🫶

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✨ SYNOPSIS ✨

🌸 Functions/Subroutines 🌸

• subroutine CSYMV (uplo, n, alpha, a, lda, x, incx, beta, y, incy) — okay so CSYMV computes a matrix-vector product for a complex symmetric matrix. that's the whole vibe. 💅

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🎀 Function/Subroutine Documentation 🎀

subroutine CSYMV (character uplo, integer n, complex alpha, complex, dimension( lda, * ) a, integer lda, complex, dimension( * ) x, integer incx, complex beta, complex, dimension( * ) y, integer incy)

So CSYMV computes a matrix-vector product for a complex symmetric matrix — no cap, that's the entire job description. 🔥

💜 Purpose:

okay bestie here's the moment, CSYMV performs the matrix-vector operation:

y := alpha*A*x + beta*y,

where alpha and beta are scalars, x and y are n element vectors, and A is an n by n symmetric matrix. that's it. that's the math. iconic. ✨

🌈 Parameters

🌸 UPLO

• UPLO is CHARACTER*1
• On entry, UPLO specifies whether the upper or lower triangular part of the array A is to be referenced, 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. 💅

🌸 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.

🌸 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.
• 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.
• Unchanged on exit.

🌸 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. 🫶

🌸 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.

🌸 INCX

• INCX is INTEGER
• On entry, INCX specifies the increment for the elements of X.
• INCX must not be zero. 🚨
• Unchanged on exit.

🌸 BETA

• BETA is COMPLEX
• On entry, BETA specifies the scalar beta. When BETA is supplied as zero then Y need not be set on input.
• Unchanged on exit.

🌸 Y

• Y is COMPLEX array, dimension at least ( 1 + ( N - 1 )*abs( INCY ) )
• Before entry, the incremented array Y must contain the n element vector y.
• On exit, Y is overwritten by the updated vector y. 🦋
• (notice it does not say "unchanged on exit" here — she gets rewritten, periodt.)

🌸 INCY

• INCY is INTEGER
• On entry, INCY specifies the increment for the elements of Y.
• INCY must not be zero. 🚨
• Unchanged on exit.

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👑 Author

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

Definition at line 156 of file csymv.f. ⭐

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🧚 Author (the meta one)

Generated automatically by Doxygen for LAPACK from the source code. not a human, just vibes and a parser. 💀

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lowkey reminder bestie: INCX and INCY must not be zero, and if you hand over BETA as zero you can skip setting Y on input. those are the only two real traps in here. 🙈

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signing off with love from the LAPACK crew — this page is from Version 3.12.0, and the whole doc was auto-magically cooked up by Doxygen from the source. slay, bye! 💖✨🎀