Roweis | Use convention over configuration to host your views | Frontend Framework library

Q1 Can I fix this error without going deep into tensorflow (I wish I could do this by staying on Keras level)

A1 I believe even if this error is fixed there are still problems in the implementation of the algorithm that keras does not support for example, the error term f(x;w_0)-y from the document is not available to a keras optimizer.

Q2 Do I use keras backend in correct way?

A2 Yes you must use the keras backend for this calculation because g is a tensor object and not a numpy array. However, I believe the correct calculation for H should be H = K.dot(K.transpose(g), g) to take the Nx1 vector g and perform an outer product to produce an NxN matrix.

Q3 This question is more about the algorith itself.

A3 As stated in A1 I am not sure that keras supports the required inputs for this algorithm.

Q4 Do I need to change in any way local file optimizers.py?

A4 The provided line of code would run the optimizer if supplied as the optimizer argument to the model compile function of keras. The keras library supports calling the built in classes and functions by name for convenience.