Not too complicated and just a different view of Ford’s circles and a way of morphing them along with a bit of animation. It’s a continuation of the previous post and there are two parts to it – the real bit and the imaginary part. The Real Part To start with we take fractions not between 0 and 1 but rather between -n and n. A rough and ready way is

1 2 3 |
-- fractionsN :: Integer -> [Fraction] fractionsN n = nub [ reduce (F p q) | p <- [-n..n], q <- [-n..n]] |

where we take all possible pairs and reduce them. Note we allow 0 as a denominator so as to be consistent with the Farey sequence. For Read More