Effective computer methods for the calculation of Rademacher-Walsh spectrum for completely and incompletely specified Boolean functions

A theory has been developed to calculate the Rademacher-Walsh t ransform f rom a cube a r r a y specification of incompletely specified Boolean functions. T h e importance of representing Boolean functions a s a r r a y s of disjoint ONa n d Ix-cubes has been pointed out , a n d a n efficient new algori thm to generate disjoint cubes f rom nondisjoint ones has been designed. The t r ans fo rm algori thm makes use of the propert ies of an a r r a y of disjoint cubes and allows the determinat ion of the spectral coefficients in a n independent way. The programs for both algorithms use advantages of C language to speed u p the execution. The comparison of different versions of the algorithm has been carr ied out . T h e presented algorithm a n d its implementation is the fastest a n d most comprehensive program (having many options) known t o us for the calculation of Rademacher-Walsh t ransform. I t successfully overcomes all drawbacks in the calculation of the t r ans fo rm f rom the design automation system based on spectral methods-the SPECSYS system f rom Drexel University tha t uses Fast Walsh Trans form.