Given an n-vector x, this function calculates the
Euclidean norm of x.
The Euclidean norm is computed by accumulating the sum of
squares in three different sums. The sums of squares for the
small and large components are scaled so that no overflows
occur. Non-destructive underflows are permitted. Underflows
and overflows do not occur in the computation of the unscaled
sum of squarees for the intermediate components.
The definitions of small, intermediate and large components
depend on two constants, rdwarf and rgiant. The main
restrictions on these constants are that rdwarf^2 not
underflow and rgiant^2 not overflow. The constants
given here are suitable for every known computer.
Given an n-vector x, this function calculates the Euclidean norm of x.
The Euclidean norm is computed by accumulating the sum of squares in three different sums. The sums of squares for the small and large components are scaled so that no overflows occur. Non-destructive underflows are permitted. Underflows and overflows do not occur in the computation of the unscaled sum of squarees for the intermediate components. The definitions of small, intermediate and large components depend on two constants, rdwarf and rgiant. The main restrictions on these constants are that rdwarf^2 not underflow and rgiant^2 not overflow. The constants given here are suitable for every known computer.