added neural networks

doc/src/week40/week40.do.txt

@@ -1200,6 +1200,21 @@ print("Test set accuracy with Logistic Regression for AND gate: {:.2f}".format(l
 
 Not exactly impressive, but somewhat better.
 
+!split
+===== Adding Neural Networks =====
+
+!bc pycod
+
+# and now neural networks with Scikit-Learn and the XOR
+
+from sklearn.neural_network import MLPClassifier
+from sklearn.datasets import make_classification
+X, yXOR = make_classification(n_samples=100, random_state=1)
+FFNN = MLPClassifier(random_state=1, max_iter=300).fit(X, yXOR)
+FFNN.predict_proba(X)
+print(f"Test set accuracy with Feed Forward Neural Network  for XOR gate:{FFNN.score(X, yXOR)}")
+
+!ec