BLAS/SRC/zher2.f(3)

✨ NAME ✨

BLAS/SRC/zher2.f — okay bestie, this page is from the Library Functions Manual, and it’s all about the BLAS subroutine zher2. Iconic linear-algebra behavior, no cap. 💅

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🌸 SYNOPSIS 🌸

✨ Functions/Subroutines ✨

• subroutine zher2 (uplo, n, alpha, x, incx, y, incy, a, lda) — ZHER2

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💅 Function/Subroutine Documentation 💅

🫶 subroutine zher2 🫶

   subroutine zher2 (character uplo, integer n, complex*16 alpha, complex*16,
       dimension(*) x, integer incx, complex*16, dimension(*) y, integer incy,
       complex*16, dimension(lda,*) a, integer lda)

ZHER2

✨ Purpose ✨

Okay so ZHER2 performs the hermitian rank 2 operation:

A := alpha*x*y**H + conjg( alpha )*y*x**H + A,

where alpha is a scalar, x and y are n element vectors and A is an n by n hermitian matrix. Literally the whole vibe. 🦋

💖 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 as follows:
  • 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.
• ALPHA — ALPHA is COMPLEX*16. 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.
• Y — Y is COMPLEX*16 array, dimension at least ( 1 + ( n - 1 )*abs( INCY ) ). Before entry, the incremented array Y must contain the n element vector y.
• INCY — INCY is INTEGER. On entry, INCY specifies the increment for the elements of Y. INCY 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. 🫶
• 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 ).

Zero increments? Not the move, bestie. INCX and INCY must not be zero. Periodt. 💀

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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.

-- 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.

Definition at line 149 of file zher2.f. 💖

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🎀 Author 🎀

Generated automatically by Doxygen for LAPACK from the source code.

💖 cute sign-off, bestie: this is BLAS/SRC/zher2.f(3) from the Library Functions Manual, source page BLAS/SRC/zher2.f, version LAPACK Version 3.12.0, and the date situation is: the footer doesn’t give a separate date, but Further Details says 22-October-1986. Mwah 💅✨