DNRM2(3)        BLAS routine of NEC Numeric Library Collection        DNRM2(3)



NAME
       DNRM2 - BLAS level one, computes the Euclidean norm of a vector

SYNOPSIS
       DOUBLE PRECISION FUNCTION DNRM2 ( n, x, incx )

           INTEGER                       n, incx

           DOUBLE PRECISION              x


DESCRIPTION
       DNRM2  computes the Euclidean (L2) norm of a double precision real vec-
       tor, as follows:

               DNRM2 <-- ||x||
                              2

       where x is a double precision real vector.

ARGUMENTS
       n       INTEGER. (input)
               Number of elements in the operand vector.

       x       DOUBLE PRECISION. (input)
               Array of dimension (n-1) * |incx| + 1.
               Array x contains the operand vector.

       incx    INTEGER. (input)
               Increment between elements of x.
               If incx = 0, the results will be unpredictable.

RETURN VALUES
       DNRM2   DOUBLE PRECISION. Result (Euclidean norm). (output)
               If n <= 0, DNRM2 is set to 0d0.

NOTES
       This routine is Level 1  Basic  Linear  Algebra  Subprograms  (Level  1
       BLAS).

       When working backward (incx < 0), each routine starts at the end of the
       vector and moves backward, as follows:

            x(1-incx * (n-1)), x(1-incx * (n-2)), ..., x(1)



BLAS routine                                                          DNRM2(3)