Efficient calculations of spectral transforms are very important for their practical applications. The efficiency is expressed in terms of
This chapter discusses methods for calculation of spectra and autocorrelations for different transforms and uses different data structures to represent the functions processed.
Methods presented in this chapter have been developed for calculations with a single processor.
Efficient techniques for calcuation of spectral transforms with multiprocessors and interconnection networks can be found in References (295, 304, and 475).
Henceforth, Walsh spectra will be used extensively as a working tool in solution of analysis and synthesis problems for network implementations of Boolean functions. We shall, therefore, devote some attention to methods for their efficient computation in terms of space and time.
We first consider an effective algorithm for construction of the Walsh spectrum and estimate its complexity. This algorithm is similar to the analogous algorithm used ...