SRC/zlargv.f(3)

💅 NAME

SRC/zlargv.f — okay so welcome to the SRC/zlargv.f(3) page from the Library Functions Manual, bestie. She’s here to serve plane rotations with real cosines and complex sines, and she ate. 💖

✨ SYNOPSIS

🧚 Functions/Subroutines

• subroutine zlargv (n, x, incx, y, incy, c, incc)
  • ZLARGV generates a vector of plane rotations with real cosines and complex sines. 🦋

🌀 Function/Subroutine Documentation

Here’s the full signature, no cap:

subroutine zlargv (integer n, complex*16, dimension( * ) x, integer incx,
    complex*16, dimension( * ) y, integer incy, double precision, dimension(
    * ) c, integer incc)

ZLARGV generates a vector of plane rotations with real cosines and complex sines. Iconic behavior, honestly.

✨ Purpose

Okay so the purpose tea is: ZLARGV generates a vector of complex plane rotations with real cosines, determined by elements of the complex vectors x and y. For i = 1,2,...,n:

(        c(i)   s(i) ) ( x(i) ) = ( r(i) )
( -conjg(s(i))  c(i) ) ( y(i) ) = (   0  )

where c(i)**2 + ABS(s(i))**2 = 1.

The following conventions are used (these are the same as in ZLARTG, but differ from the BLAS1 routine ZROTG):

• If y(i)=0, then c(i)=1 and s(i)=0.
• If x(i)=0, then c(i)=0 and s(i) is chosen so that r(i) is real. 🫶

🎀 Parameters

• N — N is INTEGER. The number of plane rotations to be generated. 💫
• X — X is COMPLEX*16 array, dimension (1+(N-1)*INCX). On entry, the vector x. On exit, x(i) is overwritten by r(i), for i = 1,...,n.
• INCX — INCX is INTEGER. The increment between elements of X. INCX > 0. 🔥
• Y — Y is COMPLEX*16 array, dimension (1+(N-1)*INCY). On entry, the vector y. On exit, the sines of the plane rotations.
• INCY — INCY is INTEGER. The increment between elements of Y. INCY > 0.
• C — C is DOUBLE PRECISION array, dimension (1+(N-1)*INCC). The cosines of the plane rotations. 🌸
• INCC — INCC is INTEGER. The increment between elements of C. INCC > 0. ✨

👑 Author

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

🔍 Further Details

• 6-6-96 - Modified with a new algorithm by W. Kahan and J. Demmel
• This version has a few statements commented out for thread safety (machine parameters are computed on each entry). 10 feb 03, SJH.

Definition at line 121 of file zlargv.f. 📌

🪄 Author

Generated automatically by Doxygen for LAPACK from the source code.

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P.S. the footer energy is LAPACK Version 3.12.0, source SRC/zlargv.f(3) — and there’s no date listed on this page, bestie, so that’s the whole footer tea. Mwah 💖🎀