• NAME
• SYNOPSIS
• F95 INTERFACE
• C INTERFACE
• PURPOSE
• ARGUMENTS

NAME

dnrm2 - Return the Euclidian norm of a vector.

SYNOPSIS

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

  DOUBLE PRECISION FUNCTION DNRM2_64( N, X, INCX)
  INTEGER*8 N, INCX
  DOUBLE PRECISION X(*)

F95 INTERFACE

  REAL(8) FUNCTION NRM2( [N], X, [INCX])
  INTEGER :: N, INCX
  REAL(8), DIMENSION(:) :: X

  REAL(8) FUNCTION NRM2_64( [N], X, [INCX])
  INTEGER(8) :: N, INCX
  REAL(8), DIMENSION(:) :: X

C INTERFACE

#include <sunperf.h>

double dnrm2(int n, double *x, int incx);

double dnrm2_64(long n, double *x, long incx);

PURPOSE

dnrm2 Return the Euclidian norm of a vector x where x is an n-vector.

ARGUMENTS

• N (input)
  On entry, N specifies the number of elements in the vector. N must be at least one for the subroutine to have any visible effect. Unchanged on exit.

• X (input)
  ( 1 + ( n - 1 )*abs( INCX ) ). On entry, the incremented array X must contain the vector x. Unchanged on exit.

• INCX (input)
  On entry, INCX specifies the increment for the elements of X. INCX must be positive. Unchanged on exit.