freq - general purpose truncating oscillator with unity amplitude

freq output[b] increment[bvpn] table[fvpn] sum[dpv] ;

A truncating, table lookup oscillator.  Dynamic variables are
recommended for sum locations. Table may be either explicit, or number
may be given.  If number is n, then function floor(n) is used.  
NOTE: This unit generator is equivalent to (but faster than) an osc with
amplitude = 1.
