BLAS/SRC/snrm2.f90(3)

💖 BLAS/SRC/snrm2.f90(3) 💖

okay bestie, welcome to the Library Functions Manual page for BLAS/SRC/snrm2.f90 — yes, the SNRM2 one. Pull up a chair, we're doing norm-girl math. ✨

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🎀 NAME 🎀

BLAS/SRC/snrm2.f90 — that's literally the name, no cap. 💅

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✨ SYNOPSIS ✨

Functions/Subroutines

• real(wp) function snrm2 (n, x, incx) — SNRM2

real(wp) function snrm2 (n, x, incx)

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🫶 Function/Subroutine Documentation 🫶

Here's the exact function signature, bestie:

real(wp) function snrm2 (integer n, real(wp), dimension(*) x, integer incx)

SNRM2 — iconic routine behavior. 👑

Purpose:

SNRM2 returns the euclidean norm of a vector via the function name, so that:

SNRM2 := sqrt( x'*x ).

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. 💀

Author

Edward Anderson, Lockheed Martin. 🫶

Date

August 2016. 🗓️

Contributors:

Weslley Pereira, University of Colorado Denver, USA. 💖

Further Details:

The receipts, verbatim:

• 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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xoxo, your Unix bestie 💖 — from LAPACK Version 3.12.0, page BLAS/SRC/snrm2.f90(3), August 2016. Slay and stay normie, in the euclidean sense. 🎀