"""
=====================================================
Plot Linear Adaptative Neuron Classifier (Adaline)
=====================================================

visualizes the Adaline estimator in action for 
improving the gradient descent through 
features scaling using the test data 
"""
# Author: L.Kouadio 
# Licence: BSD-3-clause

#%%
# Fetch the data 
import matplotlib.pyplot as plt 
from watex.base import AdalineGradientDescent 
from watex.analysis import decision_region 
from watex.datasets import fetch_data 
X, y = fetch_data ('bagoue prepared data') 

fig, axe = plt.subplots (1, 2)
agd= AdalineGradientDescent (n_iter=15, eta=.01).fit(X.toarray(), y )
decision_region(X.toarray(), y, clf=agd, return_axe=True, axe= axe[0]) # test set view
axe[0].set_title ("Adaline - Gradient descent")

axe[1].plot(range (1, len(agd.cost_) +1 ), agd.cost_, marker ="o")
axe[1].set_xlabel ("Epochs")
axe[1].set_ylabel ("Sum-squared-error")
plt.tight_layout()
plt.show()