JavaScript doesn't have tanh built in, so you have to use an approximate: http://stackoverflow.com/questions/6118028/fast-hyperbolic-tangent-approximation-in-j

JavaScript doesn't have tanh built in, so you have to use an approximate: http://stackoverflow.com/questions/6118028/fast-hyperbolic-tangent-approximation-in-javascript http://stackoverflow.com/questions/6118028/fast-hyperbolic-t...