edit

Author: MorvanZhou

tensorflowTUT/tf22_scope/tf22_RNN_scope.py

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+# visit https://morvanzhou.github.io/tutorials/ for more!
+
+
+# 22 scope (name_scope/variable_scope)
+from __future__ import print_function
+import tensorflow as tf
+
+class TrainConfig:
+    batch_size = 20
+    time_steps = 20
+    input_size = 10
+    output_size = 2
+    cell_size = 11
+    learning_rate = 0.01
+
+
+class TestConfig(TrainConfig):
+    time_steps = 1
+
+
+class RNN(object):
+
+    def __init__(self, config):
+        self._batch_size = config.batch_size
+        self._time_steps = config.time_steps
+        self._input_size = config.input_size
+        self._output_size = config.output_size
+        self._cell_size = config.cell_size
+        self._lr = config.learning_rate
+        self._built_RNN()
+
+    def _built_RNN(self):
+        with tf.variable_scope('inputs'):
+            self._xs = tf.placeholder(tf.float32, [self._batch_size, self._time_steps, self._input_size], name='xs')
+            self._ys = tf.placeholder(tf.float32, [self._batch_size, self._time_steps, self._output_size], name='ys')
+        with tf.name_scope('RNN'):
+            with tf.variable_scope('input_layer'):
+                l_in_x = tf.reshape(self._xs, [-1, self._input_size], name='2_2D')  # (batch*n_step, in_size)
+                # Ws (in_size, cell_size)
+                Wi = self._weight_variable([self._input_size, self._cell_size])
+                print(Wi.name)
+                # bs (cell_size, )
+                bi = self._bias_variable([self._cell_size, ])
+                # l_in_y = (batch * n_steps, cell_size)
+                with tf.name_scope('Wx_plus_b'):
+                    l_in_y = tf.matmul(l_in_x, Wi) + bi
+                l_in_y = tf.reshape(l_in_y, [-1, self._time_steps, self._cell_size], name='2_3D')
+
+            with tf.variable_scope('cell'):
+                cell = tf.nn.rnn_cell.BasicRNNCell(self._cell_size)
+                with tf.name_scope('initial_state'):
+                    self._cell_initial_state = cell.zero_state(self._batch_size, dtype=tf.float32)
+
+                self.cell_outputs = []
+                cell_state = self._cell_initial_state
+                for t in range(self._time_steps):
+                    if t > 0: tf.get_variable_scope().reuse_variables()
+                    cell_output, cell_state = cell(l_in_y[:, t, :], cell_state)
+                    self.cell_outputs.append(cell_output)
+                self._cell_final_state = cell_state
+
+            with tf.variable_scope('output_layer'):
+                # cell_outputs_reshaped (BATCH*TIME_STEP, CELL_SIZE)
+                cell_outputs_reshaped = tf.reshape(tf.concat(1, self.cell_outputs), [-1, self._cell_size])
+                Wo = self._weight_variable((self._cell_size, self._output_size))
+                bo = self._bias_variable((self._output_size,))
+                product = tf.matmul(cell_outputs_reshaped, Wo) + bo
+                # _pred shape (batch*time_step, output_size)
+                self._pred = tf.nn.relu(product)    # for displacement
+
+        with tf.name_scope('cost'):
+            _pred = tf.reshape(self._pred, [self._batch_size, self._time_steps, self._output_size])
+            mse = self.ms_error(_pred, self._ys)
+            mse_ave_across_batch = tf.reduce_mean(mse, 0)
+            mse_sum_across_time = tf.reduce_sum(mse_ave_across_batch, 0)
+            self._cost = mse_sum_across_time
+            self._cost_ave_time = self._cost / self._time_steps
+
+        with tf.name_scope('trian'):
+            self._lr = tf.convert_to_tensor(self._lr)
+            self.train_op = tf.train.AdamOptimizer(self._lr).minimize(self._cost)
+
+    @staticmethod
+    def ms_error(y_pre, y_target):
+        return tf.square(tf.sub(y_pre, y_target))
+
+    @staticmethod
+    def _weight_variable(shape, name='weights'):
+        initializer = tf.random_normal_initializer(mean=0., stddev=0.5, )
+        return tf.get_variable(shape=shape, initializer=initializer, name=name)
+
+    @staticmethod
+    def _bias_variable(shape, name='biases'):
+        initializer = tf.constant_initializer(0.1)
+        return tf.get_variable(name=name, shape=shape, initializer=initializer)
+
+
+if __name__ == '__main__':
+    train_config = TrainConfig()
+    test_config = TestConfig()
+
+    # the wrong method to reuse parameters in train rnn
+    with tf.variable_scope('train_rnn'):
+        train_rnn1 = RNN(train_config)
+    with tf.variable_scope('test_rnn'):
+        test_rnn1 = RNN(test_config)
+
+    # the right method to reuse parameters in train rnn
+    with tf.variable_scope('rnn') as scope:
+        sess = tf.Session()
+        train_rnn2 = RNN(train_config)
+        scope.reuse_variables()
+        test_rnn2 = RNN(test_config)
+        # tf.initialize_all_variables() no long valid from
+        # 2017-03-02 if using tensorflow >= 0.12
+        if int((tf.__version__).split('.')[1]) < 12 and int((tf.__version__).split('.')[0]) < 1:
+            init = tf.initialize_all_variables()
+        else:
+            init = tf.global_variables_initializer()
+        sess.run(init)