from cleverhans.picklable_model import MLP, Dropout from six.moves import range import tensorflow as tf def test_no_drop(): # Make sure dropout does nothing by default (so it does not cause # stochasticity at test time) model = MLP(input_shape=[1, 1], layers=[Dropout(name='output')]) x = tf.constant([[1]], dtype=tf.float32) y = model.get_layer(x, 'output') sess = tf.Session() # Do multiple runs because dropout is stochastic for i in range(10): y_value = sess.run(y) assert y_value == 1. def test_drop(): # Make sure dropout is activated successfully # We would like to configure the test to deterministically drop, # so that the test does not need to use multiple runs. # However, tf.nn.dropout divides by include_prob, so zero or # infinitesimal include_prob causes NaNs. # 1e-8 does not cause NaNs and shouldn't be a significant source # of test flakiness relative to dependency downloads failing, etc. model = MLP(input_shape=[1, 1], layers=[Dropout(name='output', include_prob=1e-8)]) x = tf.constant([[1]], dtype=tf.float32) y = model.get_layer(x, 'output', dropout=True) sess = tf.Session() y_value = sess.run(y) # Subject to very rare random failure because include_prob is not exact 0 assert y_value == 0., y_value def test_override(): # Make sure dropout_dict changes dropout probabilities successful # We would like to configure the test to deterministically drop, # so that the test does not need to use multiple runs. # However, tf.nn.dropout divides by include_prob, so zero or # infinitesimal include_prob causes NaNs. # For this test, random failure to drop will not cause the test to fail. # The stochastic version should not even run if everything is working # right. model = MLP(input_shape=[1, 1], layers=[Dropout(name='output', include_prob=1e-8)]) x = tf.constant([[1]], dtype=tf.float32) dropout_dict = {'output': 1.} y = model.get_layer(x, 'output', dropout=True, dropout_dict=dropout_dict) sess = tf.Session() y_value = sess.run(y) assert y_value == 1., y_value