C Library Functions - snrm2 (3)
NAME
snrm2(3f) - [BLAS:SINGLE_BLAS_LEVEL1] SNRM2 := square root of sum of SX(I)**2
CONTENTS
Synopsis
Definition
Options
Authors
Further Details
See Also
SYNOPSIS
real function snrm2(n,x,incx)
.. Scalar Arguments .. integer,intent(in) :: incx, n .. .. Array Arguments .. real(wp),intent(in) :: x(*) ..
DEFINITION
SNRM2 returns the euclidean norm of a vector via the function name, so that
SNRM2 := sqrt( x’*x ).
OPTIONS
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.
AUTHORS
o Edward Anderson, Lockheed Martin date:August 2016\par 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
SEE ALSO
Online html documentation available at http://www.netlib.org/lapack/explore-html/
| Nemo Release 3.1 | snrm2 (3) | February 23, 2025 |
