BLAS/SRC/zher.f(3)

✨ NAME ✨</p>

BLAS/SRC/zher.f — bestie, this is the source file for the zher subroutine, and it's about to be your new fave 💖

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🦋 SYNOPSIS 🦋

Functions/Subroutines

• subroutine zher (uplo, n, alpha, x, incx, a, lda) — no cap, that's the whole call, and yes it's giving ZHER 👑

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🌸 Function/Subroutine Documentation 🌸

subroutine zher (character uplo, integer n, double precision alpha, complex*16, dimension(*) x, integer incx, complex*16, dimension(lda,*) a, integer lda)

ZHER

💅 Purpose 💅

okay so ZHER performs the hermitian rank 1 operation, and it is literally iconic:

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

where alpha is a real scalar, x is an n element vector and A is an n by n hermitian matrix. slay 🫶

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🎀 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, fr fr:
  • 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.
• N — N is INTEGER. On entry, N specifies the order of the matrix A. N must be at least zero. (zero is allowed bestie, we don't judge 🙈)
• ALPHA — ALPHA is DOUBLE PRECISION. On entry, ALPHA specifies the scalar alpha.
• X — X is COMPLEX*16 array, dimension at least ( 1 + ( n - 1 )*abs( INCX ) ). Before entry, the incremented array X must contain the n element vector x.
• INCX — INCX is INTEGER. On entry, INCX specifies the increment for the elements of X. INCX must not be zero. 🚫
• A — A is COMPLEX*16 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 hermitian 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 hermitian 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.
  • Note that the imaginary parts of the diagonal elements need not be set, they are assumed to be zero, and on exit they are set to zero. (the glow-up of the diagonal, honestly ✨)
• 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 ).

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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 2 Blas routine. periodt 💅
• -- Written on 22-October-1986.
  • Jack Dongarra, Argonne National Lab.
  • Jeremy Du Croz, Nag Central Office.
  • Sven Hammarling, Nag Central Office.
  • Richard Hanson, Sandia National Labs.

(vintage legends, we stan 🫶)

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Definition at line 134 of file zher.f.

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Author

Generated automatically by Doxygen for LAPACK from the source code.

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💖 okay that's the whole thing bestie — LAPACK Version 3.12.0, dated Tue Nov 28 2023 12:08:41, from BLAS/SRC/zher.f(3). go forth and multiply your matrices, iykyk 🌈💜