SNRM2(3)

💖 SNRM2(3) — Library Functions Manual 💖

okay bestie, welcome to the SNRM2(3) glow-up from the Library Functions Manual. The page is tagged /home/abui...C/snrm2.f90(3) (the original header has it on both sides — we see you 👀). This is LAPACK's Euclidean-norm girlie, and she's serving main character energy in Fortran. ✨

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🎀 NAME 🎀

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/BLAS/SRC/snrm2.f90

That's the whole name section, periodt. 💅

🦋 SYNOPSIS 🦋

✨ Functions/Subroutines ✨

real(wp) function SNRM2 (n, x, incx)
    SNRM2

🌸 Function/Subroutine Documentation 🌸

real(wp) function SNRM2 (integer n, real(wp), dimension(*) x, integer incx)
    SNRM2

🎯 Purpose 🎯

!>
!> SNRM2 returns the euclidean norm of a vector via the function
!> name, so that
!>
!>    SNRM2 := sqrt( x'*x ).
!>

The way that this is literally the Euclidean norm vibe check: SNRM2 := sqrt( x'*x ). Obsessed. 🫶

🧚 Parameters 🧚

🌟 N

!>          N is INTEGER
!>         number of elements in input vector(s)
!>

🌟 X

!>          X is REAL array, dimension ( 1 + ( N - 1 )*abs( INCX ) )
!>

🌟 INCX

!>          INCX is INTEGER, storage spacing between elements of X
!>          If INCX > 0, X(1+(i-1)*INCX) = x(i) for 1 <= i <= n
!>          If INCX < 0, X(1-(n-i)*INCX) = x(i) for 1 <= i <= n
!>          If INCX = 0, x isn't a vector so there is no need to call
!>          this subroutine.  If you call it anyway, it will count x(1)
!>          in the vector norm N times.
!>

bestie, if INCX = 0, x isn't a vector so there is literally no need to call this subroutine. But if you call it anyway, it will count x(1) in the vector norm N times. That's the rule — iykyk. 💀

💖 Author 💖

Edward Anderson, Lockheed Martin

📅 Date 📅

August 2016

🫶 Contributors 🫶

Weslley Pereira, University of Colorado Denver, USA

📚 Further Details 📚

!>
!>  Anderson E. (2017)
!>  Algorithm 978: Safe Scaling in the Level 1 BLAS
!>  ACM Trans Math Softw 44:1--28
!>  https://doi.org/10.1145/3061665
!>
!>  Blue, James L. (1978)
!>  A Portable Fortran Program to Find the Euclidean Norm of a Vector
!>  ACM Trans Math Softw 4:15--23
!>  https://doi.org/10.1145/355769.355771
!>
!>

Definition at line 88 of file snrm2.f90.

💫 Author 💫

Generated automatically by Doxygen for LAPACK from the source code.

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mwah 💋 — this was LAPACK Version 3.12.0, page /home/abui...C/snrm2.f90(3), dated August 2016. Stay sliving, bestie 🎀✨