What is the use of verbose in Keras while validating the model?

Question:

I’m running the LSTM model for the first time.
Here is my model:

opt = Adam(0.002)
inp = Input(...)
print(inp)
x = Embedding(....)(inp)
x = LSTM(...)(x)
x = BatchNormalization()(x)
pred = Dense(5,activation='softmax')(x)

model = Model(inp,pred)
model.compile(....)

idx = np.random.permutation(X_train.shape[0])
model.fit(X_train[idx], y_train[idx], nb_epoch=1, batch_size=128, verbose=1)

What is the use of verbose while training the model?

Asked By: rakesh

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Answers:

Check documentation for model.fit here.

By setting verbose 0, 1 or 2 you just say how do you want to ‘see’ the training progress for each epoch.

verbose=0 will show you nothing (silent)

verbose=1 will show you an animated progress bar like this:

progres_bar

verbose=2 will just mention the number of epoch like this:

enter image description here

Answered By: Ankit

For verbose > 0, fit method logs:

  • loss: value of loss function for your training data
  • acc: accuracy value for your training data.

Note: If regularization mechanisms are used, they are turned on to avoid overfitting.

if validation_data or validation_split arguments are not empty, fit method logs:

  • val_loss: value of loss function for your validation data
  • val_acc: accuracy value for your validation data

Note: Regularization mechanisms are turned off at testing time because we are using all the capabilities of the network.

For example, using verbose while training the model helps to detect overfitting which occurs if your acc keeps improving while your val_acc gets worse.

Answered By: Hugo Bevilacqua

verbose: Integer. 0, 1, or 2. Verbosity mode.

Verbose=0 (silent)

Verbose=1 (progress bar)

Train on 186219 samples, validate on 20691 samples
Epoch 1/2
186219/186219 [==============================] - 85s 455us/step - loss: 0.5815 - acc: 
0.7728 - val_loss: 0.4917 - val_acc: 0.8029
Train on 186219 samples, validate on 20691 samples
Epoch 2/2
186219/186219 [==============================] - 84s 451us/step - loss: 0.4921 - acc: 
0.8071 - val_loss: 0.4617 - val_acc: 0.8168

Verbose=2 (one line per epoch)

Train on 186219 samples, validate on 20691 samples
Epoch 1/1
 - 88s - loss: 0.5746 - acc: 0.7753 - val_loss: 0.4816 - val_acc: 0.8075
Train on 186219 samples, validate on 20691 samples
Epoch 1/1
 - 88s - loss: 0.4880 - acc: 0.8076 - val_loss: 0.5199 - val_acc: 0.8046

By default verbose = 1,

verbose = 1, which includes both progress bar and one line per epoch

verbose = 0, means silent

verbose = 2, one line per epoch i.e. epoch no./total no. of epochs

Answered By: Ashiq Imran

The order of details provided with verbose flag are as

Less details…. More details

0 < 2 < 1

Default is 1

For production environment, 2 is recommended

Answered By: DevLoverUmar

verbose is the choice that how you want to see the output of your Nural Network while it’s training.
If you set verbose = 0, It will show nothing

If you set verbose = 1, It will show the output like this
Epoch 1/200
55/55[==============================] – 10s 307ms/step – loss: 0.56 – accuracy: 0.4949

If you set verbose = 2, The output will be like
Epoch 1/200
Epoch 2/200
Epoch 3/200

Answered By: Md. Imrul Kayes