DZNRM2(3) BLAS routine of NEC Numeric Library Collection DZNRM2(3)
NAME
DZNRM2 - BLAS level one, computes the Euclidean norm of a vector
SYNOPSIS
DOUBLE PRECISION FUNCTION DZNRM2 ( n, x, incx )
INTEGER n, incx
DOUBLE COMPLEX x
DESCRIPTION
DZNRM2 computes the Euclidean (L2) norm of a double precision complex
vector:
DZNRM2 <-- ||x||
2
where x is a double precision complex vector.
ARGUMENTS
n INTEGER (input)
Number of elements in the operand vector.
x DOUBLE COMPLEX (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
DZNRM2 DOUBLE PRECISION Result (Euclidean norm). (output)
If n <= 0, DZNRM2 is set to 0d0.
NOTES
This routine is Level 1 Basic Linear Algebra Subprograms (Level 1
BLAS).
When working backward (incx < 0), DZNRM2 starts at the end of the vec-
tor and moves backward, as follows:
x(1-incx * (n-1)), x(1-incx * (n-2)), ..., x(1)
BLAS routine DZNRM2(3)