OperatorChebyshevSeries

A Chebyshev series operator is defined in terms of a Chebyshev series and an operator. It applies the Chebyshev series to the operator when acting on vectors. For example, a Chebyshev series $p(x) = \sum_{n=0}^{N} a_n T_n(x)$ becomes $p(A) = \sum_{n=0}^{N} a_n T_n(A)$ when applied to an operator $A$, where $T_n$ are the Chebyshev polynomials.