. "Also in the embodiment, the discrete values within each sub-range divide the sub-range equally, and instead of having to look up the s'th value in the e'th sub-range, s is considered to range from 0 to 1 and the 1/w value represented by (e,s) can be calculated from e and s according to the function 1/w=s???2-be, where b is a parameter which can in general vary with e." . . .