“…However, the latter method has computational complexity and storage requirement dependent upon the square of the number of candidate terms that are searched, while in FOS the dependence is reduced to a linear relationship. In addition FOS and/or iterative forms [44 -47] of FOS have been used for high-resolution spectral analysis [42,45,47,48], direction finding [44,45], constructing generalized single-layer networks [46], and design of two-dimensional filters [49], among many applications. Wu et al [50] have compared FOS with canonical variate analysis for biological applications.…”