Technical Reference: Base Operating System and Extensions , Volume 2

SNRM2, DNRM2, SCNRM2, or DZNRM2 Function

Computes the Euclidean length of the N-vector stored in X() with storage increment INCX.

BLAS Library (libblas.a)

REAL FUNCTION SNRM2(N,X,INCX) INTEGER INCX, N REAL X(*)

DOUBLE PRECISION FUNCTION DNRM2(N,X,INCX)
INTEGER INCX,N
DOUBLE PRECISION X(*)

REAL FUNCTION SCNRM2(N,X,INCX)
INTEGER INCX,N
COMPLEX X(*)

DOUBLE PRECISION FUNCTION DZNRM2(N,X,INCX)
INTEGER INCX,N
COMPLEX*16 X(*)

The SNRM2, DNRM2, SCNRM2, or DZNRM2 function returns the Euclidean norm of the N-vector stored in X() with storage increment INCX.

N	On entry, N specifies the number of elements in X and Y; unchanged on exit.
X	Vector of dimension at least (1 + (N-1) * abs(INCX) ); unchanged on exit.
INCX	On entry, INCX specifies the increment for the elements of X; INCX must be greater than 0; unchanged on exit.

For values of N <= 0, a value of 0 is returned.