fixed-point tips

Another thing I forgot to mention - it can get more complicated when you do something like using a range -0.5 to + 0.5

With this, you can actually gain accuracy because you can use "imaginary" bits. This comes in handy when you have 18 bit hardware multipliers but your values need to be in the range something like -(2^-18) to 2^-18 (ie. very small) where the most sig. 18 bits are all sign bits.

So you represent what would be a 36 bit number in 18 bits, with an "imagniary" 18 bits on the front. For full accuracy on the result, you'd need a 72 bit number - 36 imaginary sign bits and 36 bits of result.