Abstract
The spectral coefficients of a switching function are computed in terms of the real transform of the function, or equivalently, in terms of a disjoint sum-of-products representation of the function. Such a representation can be cast into an almost minimal form through some existing algorithms, and its complexity can be significantly less than that of a minterm expansion, which it includes as a special case. The real transform is also utilized as a mechanism for the inverse transform from the spectral domain to the Boolean domain.