[tchow]

How do you know to choose 6 hidden layers with 6 neurons each though? Why not 'x' hidden layers with 'j' neurons each? or some other random number?

Also how do you know to choose a ReLu instead of a Tanh activation?

[espadrine]

ReLu gives good results for deep learning: http://jmlr.org/proceedings/papers/v15/glorot11a/glorot11a.p....

6 layers is the maximum that this demonstration allows, and they kept j small-ish to show that you don't need that many to have good results.