FIX: move the BatchNormalization before the activation with no bias (#531)

Author: glemaitre

doc/whats_new/v0.5.rst

@@ -22,3 +22,12 @@ Maintenance
 
 - Make it possible to ``import imblearn`` and access submodule.
   :issue:`500` by :user:`Guillaume Lemaitre <glemaitre>`.
+
+Bug
+...
+
+- Fix wrong usage of :class:`keras.layers.BatchNormalization` in
+  ``porto_seguro_keras_under_sampling.py`` example. The batch normalization
+  was moved before the activation function and the bias was removed from the
+  dense layer.
+  :issue:`531` by :user:`Guillaume Lemaitre <glemaitre>`.

examples/applications/porto_seguro_keras_under_sampling.py

@@ -98,20 +98,20 @@ def make_model(n_features):
     model = Sequential()
     model.add(Dense(200, input_shape=(n_features,),
               kernel_initializer='glorot_normal'))
-    model.add(Activation('relu'))
     model.add(BatchNormalization())
-    model.add(Dropout(0.5))
-    model.add(Dense(100, kernel_initializer='glorot_normal'))
     model.add(Activation('relu'))
+    model.add(Dropout(0.5))
+    model.add(Dense(100, kernel_initializer='glorot_normal', use_bias=False))
     model.add(BatchNormalization())
-    model.add(Dropout(0.25))
-    model.add(Dense(50, kernel_initializer='glorot_normal'))
     model.add(Activation('relu'))
+    model.add(Dropout(0.25))
+    model.add(Dense(50, kernel_initializer='glorot_normal', use_bias=False))
     model.add(BatchNormalization())
-    model.add(Dropout(0.15))
-    model.add(Dense(25, kernel_initializer='glorot_normal'))
     model.add(Activation('relu'))
+    model.add(Dropout(0.15))
+    model.add(Dense(25, kernel_initializer='glorot_normal', use_bias=False))
     model.add(BatchNormalization())
+    model.add(Activation('relu'))
     model.add(Dropout(0.1))
     model.add(Dense(1, activation='sigmoid'))