1. Apparatus for generating waveforms, said apparatus comprising: first memory means for storing a plurality of generator equations, said generator equations corresponding to Portmanteau functions; second memory means for storing discrete values of a parameter defining an argument for said generator equations stored in said first memory means; a processing means receiving at least one of said plurality of generator equations from said first memory means and receiving a sequence of said discrete values from said second memory means for generating a sequence of values corresponding to a calculated result of said at least one generator equation using said sequence of discrete values as said arguments therein; and means for providing said sequence of values in a succession so as define successive segments of a waveform.