Table 9.

A comparison of the computational complexity between the IIF2, iETD2, hIFE2, and fEIF2 methods.

	Operations per iteration	Total complexity (ratio)
IIF2	$\mathcal{O}\left(N^2\right)$	1
iETD2	$\mathcal{O}\left(\kappa N^3\right)$	$\mathcal{O}\left(\kappa N\right)$
hIFE2	$\mathcal{O}\left(3N^2\right)$	3
fEIF2	$\mathcal{O}\left(5N^2\right)$	5