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How to use TensorLayer

While research in Deep Learning continues to improve the world, we use a bunch of tricks to implement algorithms with TensorLayer day to day.

Here are a summary of the tricks to use TensorLayer. If you find a trick that is particularly useful in practice, please open a Pull Request to add it to the document. If we find it to be reasonable and verified, we will merge it in.

1. Installation

2. Interaction between TF and TL

3. Training/Testing switching

def mlp(x, is_train=True, reuse=False):
    with tf.variable_scope("MLP", reuse=reuse):
      net = InputLayer(x, name='in')
      net = DropoutLayer(net, 0.8, True, is_train, name='drop1')
      net = DenseLayer(net, n_units=800, act=tf.nn.relu, name='dense1')
      net = DropoutLayer(net, 0.8, True, is_train, name='drop2')
      net = DenseLayer(net, n_units=800, act=tf.nn.relu, name='dense2')
      net = DropoutLayer(net, 0.8, True, is_train, name='drop3')
      net = DenseLayer(net, n_units=10, act=tf.identity, name='out')
      logits = net.outputs
      net.outputs = tf.nn.sigmoid(net.outputs)
      return net, logits
x = tf.placeholder(tf.float32, shape=[None, 784], name='x')
y_ = tf.placeholder(tf.int64, shape=[None, ], name='y_')
net_train, logits = mlp(x, is_train=True, reuse=False)
net_test, _ = mlp(x, is_train=False, reuse=True)
cost = tl.cost.cross_entropy(logits, y_, name='cost')

More in here.

4. Get variables and outputs

train_vars = tl.layers.get_variables_with_name('MLP', True, True)
train_op = tf.train.AdamOptimizer(learning_rate=0.0001).minimize(cost, var_list=train_vars)
layers = tl.layers.get_layers_with_name(network, "MLP", True)

5. Data augmentation for large dataset

If your dataset is large, data loading and data augmentation will become the bottomneck and slow down the training. To speed up the data processing you can:

6. Data augmentation for small dataset

If your data size is small enough to feed into the memory of your machine, and data augmentation is simple. To debug easily, you can:

7. Pre-trained CNN and Resnet

8. Using tl.models

x = tf.placeholder(tf.float32, [None, 224, 224, 3])
# get the whole model
vgg = tl.models.VGG16(x)
# restore pre-trained VGG parameters
sess = tf.InteractiveSession()
vgg.restore_params(sess)
# use for inferencing
probs = tf.nn.softmax(vgg.outputs)
x = tf.placeholder(tf.float32, [None, 224, 224, 3])
# get VGG without the last layer
vgg = tl.models.VGG16(x, end_with='fc2_relu')
# add one more layer
net = tl.layers.DenseLayer(vgg, 100, name='out')
# initialize all parameters
sess = tf.InteractiveSession()
tl.layers.initialize_global_variables(sess)
# restore pre-trained VGG parameters
vgg.restore_params(sess)
# train your own classifier (only update the last layer)
train_params = tl.layers.get_variables_with_name('out')
x1 = tf.placeholder(tf.float32, [None, 224, 224, 3])
x2 = tf.placeholder(tf.float32, [None, 224, 224, 3])
# get VGG without the last layer
vgg1 = tl.models.VGG16(x1, end_with='fc2_relu')
# reuse the parameters of vgg1 with different input
vgg2 = tl.models.VGG16(x2, end_with='fc2_relu', reuse=True)
# restore pre-trained VGG parameters (as they share parameters, we don’t need to restore vgg2)
sess = tf.InteractiveSession()
vgg1.restore_params(sess)

9. Customized layer

import tensorflow as tf
import tensorlayer as tl
from keras.layers import *
from tensorlayer.layers import *
def my_fn(x):
    x = Dropout(0.8)(x)
    x = Dense(800, activation='relu')(x)
    x = Dropout(0.5)(x)
    x = Dense(800, activation='relu')(x)
    x = Dropout(0.5)(x)
    logits = Dense(10, activation='linear')(x)
    return logits

network = InputLayer(x, name='input')
network = LambdaLayer(network, my_fn, name='keras')
...

10. Sentences tokenization

>>> captions = ["one two , three", "four five five"] # 2个 句 子 
>>> processed_capts = []
>>> for c in captions:
>>>    c = tl.nlp.process_sentence(c, start_word="<S>", end_word="</S>")
>>>    processed_capts.append(c)
>>> print(processed_capts)
... [['<S>', 'one', 'two', ',', 'three', '</S>'],
... ['<S>', 'four', 'five', 'five', '</S>']]
>>> tl.nlp.create_vocab(processed_capts, word_counts_output_file='vocab.txt', min_word_count=1)
... [TL] Creating vocabulary.
... Total words: 8
... Words in vocabulary: 8
... Wrote vocabulary file: vocab.txt
>>> vocab = tl.nlp.Vocabulary('vocab.txt', start_word="<S>", end_word="</S>", unk_word="<UNK>")
... INFO:tensorflow:Initializing vocabulary from file: vocab.txt
... [TL] Vocabulary from vocab.txt : <S> </S> <UNK>
... vocabulary with 10 words (includes start_word, end_word, unk_word)
...   start_id: 2
...   end_id: 3
...   unk_id: 9
...   pad_id: 0

Then you can map word to ID or vice verse as follow:

>>> vocab.id_to_word(2)
... 'one'
>>> vocab.word_to_id('one')
... 2
>>> vocab.id_to_word(100)
... '<UNK>'
>>> vocab.word_to_id('hahahaha')
... 9

11. Dynamic RNN and sequence length

>>> sequences = [[1,1,1,1,1],[2,2,2],[3,3]]
>>> sequences = tl.prepro.pad_sequences(sequences, maxlen=None, 
...         dtype='int32', padding='post', truncating='pre', value=0.)
... [[1 1 1 1 1]
...  [2 2 2 0 0]
...  [3 3 0 0 0]]
>>> data = [[1,2,0,0,0], [1,2,3,0,0], [1,2,6,1,0]]
>>> o = tl.layers.retrieve_seq_length_op2(data)
>>> sess = tf.InteractiveSession()
>>> tl.layers.initialize_global_variables(sess)
>>> print(o.eval())
... [2 3 4]

12. Save models

13. Compatibility with other TF wrappers

TL can interact with other TF wrappers, which means if you find some codes or models implemented by other wrappers, you can just use it !

14. Others

Useful links

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