HP MLIB User's Guide Vol. 1 7th Ed.

Chapter 2 Basic Vector Operations 107
Euclidean norm SNRM2/DNRM2/SCNRM2/DZNRM2
Name SNRM2/DNRM2/SCNRM2/DZNRM2
Euclidean norm
Purpose Given a real or complex vector x of length n, these subprograms compute the
Euclidean (that is, l
2
) norm of the vector
The vector can be stored in a one-dimensional array or in either a row or a
column of a two-dimensional array.
Usage VECLIB:
INTEGER*4 n, incx
REAL*4 s, SNRM2, x(lenx)
s = SNRM2(n, x, incx)
INTEGER*4 n, incx
REAL*8 s, DNRM2, x(lenx)
s = DNRM2(n, x, incx)
INTEGER*4 n, incx
REAL*4 s, SCNRM2
COMPLEX*8 x(lenx)
s = SCNRM2(n, x, incx)
INTEGER*4 n, incx
REAL*8 s, DZNRM2
COMPLEX*16 x(lenx)
s = DZNRM2(n, x, incx)
VECLIB8:
INTEGER*8 n, incx
REAL*4 s, SNRM2, x(lenx)
s = SNRM2(n, x, incx)
INTEGER*8 n, incx
REAL*8 s, DNRM2, x(lenx)
s = DNRM2(n, x, incx)
INTEGER*8 n, incx
REAL*4 s, SCNRM2
COMPLEX*8 x(lenx)
s = SCNRM2(n, x, incx)
sx
2
x
i
2
i 1=
n
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