I'm trying to figure out why model's Loss value is always 0.0, so the accuracy seems to be constant as well (which is incorrect in my case, afaik).
Code snippet:
model = Sequential()
model.add(Embedding(vocab_size, glove_vectors.vector_size, weights=[embedding_matrix], input_length=X.shape[1]))
model.add(Dropout(0.5))
model.add(LSTM(100, dropout=0.2, recurrent_dropout=0.2))
model.add(Dense(1, activation="sigmoid"))
model.compile(loss='categorical_crossentropy', optimizer="adam", metrics=["accuracy"])
model.summary()
EPOCHS = 20
train_data, test_data, train_labels, test_labels = train_test_split(X, Y, test_size=0.20, random_state = 42)
print(train_data.shape, train_labels.shape)
print(test_data.shape, test_labels.shape)
val_data = (test_data, test_labels)
history = model.fit(train_data, train_labels, validation_data=val_data, epochs=EPOCHS)
score = model.evaluate(test_data, test_labels)
Output:
Epoch 1/20
25/25 [==============================] - 4s 69ms/step - loss: 0.0000e+00 - accuracy: 0.5241 - val_loss: 0.0000e+00 - val_accuracy: 0.4650
Epoch 2/20
25/25 [==============================] - 1s 55ms/step - loss: 0.0000e+00 - accuracy: 0.4927 - val_loss: 0.0000e+00 - val_accuracy: 0.4650
Epoch 3/20
25/25 [==============================] - 1s 55ms/step - loss: 0.0000e+00 - accuracy: 0.5110 - val_loss: 0.0000e+00 - val_accuracy: 0.4650
Epoch 4/20
25/25 [==============================] - 1s 56ms/step - loss: 0.0000e+00 - accuracy: 0.5074 - val_loss: 0.0000e+00 - val_accuracy: 0.4650
Epoch 5/20
25/25 [==============================] - 1s 55ms/step - loss: 0.0000e+00 - accuracy: 0.5363 - val_loss: 0.0000e+00 - val_accuracy: 0.4650
Epoch 6/20
25/25 [==============================] - 1s 53ms/step - loss: 0.0000e+00 - accuracy: 0.5042 - val_loss: 0.0000e+00 - val_accuracy: 0.4650
Epoch 7/20
25/25 [==============================] - 1s 54ms/step - loss: 0.0000e+00 - accuracy: 0.4904 - val_loss: 0.0000e+00 - val_accuracy: 0.4650
In binary classification there will be 1
node in the output layer even though we will be predicting between two classes. In order to get the output in a probability format between 0
and 1
we will use the sigmoid
function.
Hence binary_crossentropy
is the correct loss function in your case
model.compile(loss='binary_crossentropy', optimizer="adam", metrics=["accuracy"])
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