BLAS/SRC/dsdot.f(3)

📦
version 3.12.0 · 7 versions
, in centos-stream 10, fedora 43, fedora 44

✨ BLAS/SRC/dsdot.f ✨

okay bestie, gather round, we're doing a LAPACK page from the LAPACK manual and honestly? this one's a little cutie. it's dsdot and it's giving "quietly doing the math so you don't have to" energy 💅

🌸 NAME 🌸

BLAS/SRC/dsdot.f — yes that's literally it, that's the whole name, she's lowkey mysterious like that 🎀

🦋 SYNOPSIS 🦋

Functions/Subroutines

double precision function dsdot (n, sx, incx, sy, incy)
    DSDOT

💖 Function/Subroutine Documentation 💖

double precision function dsdot (integer n, real, dimension(*) sx, integer
    incx, real, dimension(*) sy, integer incy)

DSDOT

🎀 Purpose:

compute the inner product of two vectors with extended precision accumulation and result ✨

basically it returns a D.P. dot product that got accumulated in D.P., for S.P. SX and SY, no cap:

DSDOT = sum for I = 0 to N-1 of  SX(LX+I*INCX) * SY(LY+I*INCY),

where LX = 1 if INCX .GE. 0, else LX = 1+(1-N)*INCX, and LY is defined in a similar way using INCY. (yes, that LX/LY thing is doing the "start from the other end when the stride is negative" dance 🕺 it's iconic, it ate)

🌈 Parameters

  • N — N is INTEGER, and it's the number of elements in the input vector(s). slay.
  • SX — SX is REAL array, dimension(N), a single precision vector with N elements. she's single and ready to mingle 🍓
  • INCX — INCX is INTEGER, the storage spacing between elements of SX. the stride, bestie, it's the stride.
  • SY — SY is REAL array, dimension(N), another single precision vector with N elements. matching set 💜
  • INCY — INCY is INTEGER, the storage spacing between elements of SY. same vibe, different axis.

⭐ Returns

  • DSDOT — DSDOT is DOUBLE PRECISION. DSDOT is the double precision dot product (zero if N.LE.0 — yeah, if there's nothing to multiply she just hands you a 0 and moves on, honestly same 🙈)

👑 Author

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

(that's four whole institutions on one lil function, main character energy fr fr)

💜 Further Details:

(this section is empty in the original — nothing but vibes and silence 🤫)

🧚 References:

C. L. Lawson, R. J. Hanson, D. R. Kincaid and F. T.
Krogh, Basic linear algebra subprograms for Fortran
usage, Algorithm No. 539, Transactions on Mathematical
Software 5, 3 (September 1979), pp. 308-323.

REVISION HISTORY (YYMMDD)

791001  DATE WRITTEN
890831  Modified array declarations.  (WRB)
890831  REVISION DATE from Version 3.2
891214  Prologue converted to Version 4.0 format.  (BAB)
920310  Corrected definition of LX in DESCRIPTION.  (WRB)
920501  Reformatted the REFERENCES section.  (WRB)
070118  Reformat to LAPACK style (JL)

look at that glow-up timeline 😭 1979 to 2007, she's been reinvented more times than my playlist. periodt.

Definition at line 118 of file dsdot.f.

🫶 Author

generated automatically by Doxygen for LAPACK from the source code. (so if you're mad about the formatting, blame the robot, not me 💀)

and that's the whole page bestie, hope the vibe check passed ✨ stay slaying, stay strided, and remember: extended precision accumulation is self care 🌸

Version 3.12.0 — Tue Nov 28 2023 12:08:41 — BLAS/SRC/dsdot.f(3) 🎀💖🦋

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