Understanding the ECOC algorithm

[arilwan]

This is not an issue but a question (not sure how to tag it as question).
a. Can you explain how the ECOC class works please? For example, generating the codeword matrix in _gen_code_matrix which invokes the _encode_dense method.
b. What the meaning of the __file__ variable passed to os.path.dirname in _encode_dense?
c. How is the codeword length chosen?
d. Suppose I decide using other algorithm (e.g. Logistic Regression, MLP, etc) as the base learner, how could this be done?