ON THE CALCULATION OF ANALYTIC FUNCTIONS OF CYCLIC MATRICES

Recently Lowdin, Pauncz, and de Heer, have discussed the calculation of functions of cyclic matrices. They presented three exact methods for doing this. We show that the last of their methods can be generalized to a method which is convenient for approximate calculations and which in addition can be extended to the calculation of functions of higher order cyclic matrices. A number of examples are presented. It is also shown that by the same techniques it is possible to evaluate functions of a skew circulant matrix.