Tensorflow。從BasicRNNCell切換到LSTMCell

Question

我已經用BasicRNN構建了一個RNN，現在我想使用LSTMCell，但這段文字看起來並不重要。我應該改變什麼？

首先我定義所有的佔位符和變量：

X_placeholder = tf.placeholder(tf.float32, [batch_size, truncated_backprop_length, embedding_size]) 
Y_placeholder = tf.placeholder(tf.int32, [batch_size, truncated_backprop_length]) 

init_state = tf.placeholder(tf.float32, [batch_size, state_size]) 

W = tf.Variable(np.random.rand(state_size, num_classes),dtype=tf.float32) 
b = tf.Variable(np.zeros((batch_size, num_classes)), dtype=tf.float32) 

W2 = tf.Variable(np.random.rand(state_size, num_classes),dtype=tf.float32) 
b2 = tf.Variable(np.zeros((batch_size, num_classes)), dtype=tf.float32) 

然後我拆散標籤：

labels_series = tf.transpose(batchY_placeholder) 
labels_series = tf.unstack(batchY_placeholder, axis=1) 
inputs_series = X_placeholder 

然後我定義我RNN：

cell = tf.contrib.rnn.BasicLSTMCell(state_size, state_is_tuple = False) 
states_series, current_state = tf.nn.dynamic_rnn(cell, inputs_series, initial_state = init_state) 

的錯誤，我得到的是：

InvalidArgumentError      Traceback (most recent call last) 
/home/deepnlp2017/.local/lib/python3.5/site-packages/tensorflow/python/framework/common_shapes.py in _call_cpp_shape_fn_impl(op, input_tensors_needed, input_tensors_as_shapes_needed, debug_python_shape_fn, require_shape_fn) 
    669   node_def_str, input_shapes, input_tensors, input_tensors_as_shapes, 

--> 670   status) 
    671 except errors.InvalidArgumentError as err: 

/home/deepnlp2017/anaconda3/lib/python3.5/contextlib.py in __exit__(self, type, value, traceback) 
    65    try: 
---> 66     next(self.gen) 
    67    except StopIteration: 

/home/deepnlp2017/.local/lib/python3.5/site-packages/tensorflow/python/framework/errors_impl.py in raise_exception_on_not_ok_status() 
    468   compat.as_text(pywrap_tensorflow.TF_Message(status)), 
--> 469   pywrap_tensorflow.TF_GetCode(status)) 
    470 finally: 

InvalidArgumentError: Dimensions must be equal, but are 50 and 100 for 'rnn/while/basic_lstm_cell/mul' (op: 'Mul') with input shapes: [32,50], [32,100]. 

During handling of the above exception, another exception occurred: 

ValueError        Traceback (most recent call last) 
<ipython-input-19-2ac617f4dde4> in <module>() 
     4 #cell = tf.contrib.rnn.BasicRNNCell(state_size) 
     5 cell = tf.contrib.rnn.BasicLSTMCell(state_size, state_is_tuple = False) 
----> 6 states_series, current_state = tf.nn.dynamic_rnn(cell, inputs_series, initial_state = init_state) 

/home/deepnlp2017/.local/lib/python3.5/site-packages/tensorflow/python/ops/rnn.py in dynamic_rnn(cell, inputs, sequence_length, initial_state, dtype, parallel_iterations, swap_memory, time_major, scope) 
    543   swap_memory=swap_memory, 
    544   sequence_length=sequence_length, 
--> 545   dtype=dtype) 
    546 
    547  # Outputs of _dynamic_rnn_loop are always shaped [time, batch, depth]. 

/home/deepnlp2017/.local/lib/python3.5/site-packages/tensorflow/python/ops/rnn.py in _dynamic_rnn_loop(cell, inputs, initial_state, parallel_iterations, swap_memory, sequence_length, dtype) 
    710  loop_vars=(time, output_ta, state), 
    711  parallel_iterations=parallel_iterations, 
--> 712  swap_memory=swap_memory) 
    713 
    714 # Unpack final output if not using output tuples. 

/home/deepnlp2017/.local/lib/python3.5/site-packages/tensorflow/python/ops/control_flow_ops.py in while_loop(cond, body, loop_vars, shape_invariants, parallel_iterations, back_prop, swap_memory, name) 
    2624  context = WhileContext(parallel_iterations, back_prop, swap_memory, name) 
    2625  ops.add_to_collection(ops.GraphKeys.WHILE_CONTEXT, context) 
-> 2626  result = context.BuildLoop(cond, body, loop_vars, shape_invariants) 
    2627  return result 
    2628 

/home/deepnlp2017/.local/lib/python3.5/site-packages/tensorflow/python/ops/control_flow_ops.py in BuildLoop(self, pred, body, loop_vars, shape_invariants) 
    2457  self.Enter() 
    2458  original_body_result, exit_vars = self._BuildLoop(
-> 2459   pred, body, original_loop_vars, loop_vars, shape_invariants) 
    2460  finally: 
    2461  self.Exit() 

/home/deepnlp2017/.local/lib/python3.5/site-packages/tensorflow/python/ops/control_flow_ops.py in _BuildLoop(self, pred, body, original_loop_vars, loop_vars, shape_invariants) 
    2407   structure=original_loop_vars, 
    2408   flat_sequence=vars_for_body_with_tensor_arrays) 
-> 2409  body_result = body(*packed_vars_for_body) 
    2410  if not nest.is_sequence(body_result): 
    2411  body_result = [body_result] 

/home/deepnlp2017/.local/lib/python3.5/site-packages/tensorflow/python/ops/rnn.py in _time_step(time, output_ta_t, state) 
    695   skip_conditionals=True) 
    696  else: 
--> 697  (output, new_state) = call_cell() 
    698 
    699  # Pack state if using state tuples 

/home/deepnlp2017/.local/lib/python3.5/site-packages/tensorflow/python/ops/rnn.py in <lambda>() 
    681 
    682  input_t = nest.pack_sequence_as(structure=inputs, flat_sequence=input_t) 
--> 683  call_cell = lambda: cell(input_t, state) 
    684 
    685  if sequence_length is not None: 

/home/deepnlp2017/.local/lib/python3.5/site-packages/tensorflow/contrib/rnn/python/ops/core_rnn_cell_impl.py in __call__(self, inputs, state, scope) 
    182  i, j, f, o = array_ops.split(value=concat, num_or_size_splits=4, axis=1) 
    183 
--> 184  new_c = (c * sigmoid(f + self._forget_bias) + sigmoid(i) * 
    185    self._activation(j)) 
    186  new_h = self._activation(new_c) * sigmoid(o) 

/home/deepnlp2017/.local/lib/python3.5/site-packages/tensorflow/python/ops/math_ops.py in binary_op_wrapper(x, y) 
    882  if not isinstance(y, sparse_tensor.SparseTensor): 
    883   y = ops.convert_to_tensor(y, dtype=x.dtype.base_dtype, name="y") 
--> 884  return func(x, y, name=name) 
    885 
    886 def binary_op_wrapper_sparse(sp_x, y): 

/home/deepnlp2017/.local/lib/python3.5/site-packages/tensorflow/python/ops/math_ops.py in _mul_dispatch(x, y, name) 
    1103 is_tensor_y = isinstance(y, ops.Tensor) 
    1104 if is_tensor_y: 
-> 1105  return gen_math_ops._mul(x, y, name=name) 
    1106 else: 
    1107  assert isinstance(y, sparse_tensor.SparseTensor) # Case: Dense * Sparse. 

/home/deepnlp2017/.local/lib/python3.5/site-packages/tensorflow/python/ops/gen_math_ops.py in _mul(x, y, name) 
    1623  A `Tensor`. Has the same type as `x`. 
    1624 """ 
-> 1625 result = _op_def_lib.apply_op("Mul", x=x, y=y, name=name) 
    1626 return result 
    1627 

/home/deepnlp2017/.local/lib/python3.5/site-packages/tensorflow/python/framework/op_def_library.py in apply_op(self, op_type_name, name, **keywords) 
    761   op = g.create_op(op_type_name, inputs, output_types, name=scope, 
    762       input_types=input_types, attrs=attr_protos, 
--> 763       op_def=op_def) 
    764   if output_structure: 
    765   outputs = op.outputs 

/home/deepnlp2017/.local/lib/python3.5/site-packages/tensorflow/python/framework/ops.py in create_op(self, op_type, inputs, dtypes, input_types, name, attrs, op_def, compute_shapes, compute_device) 
    2395      original_op=self._default_original_op, op_def=op_def) 
    2396  if compute_shapes: 
-> 2397  set_shapes_for_outputs(ret) 
    2398  self._add_op(ret) 
    2399  self._record_op_seen_by_control_dependencies(ret) 

/home/deepnlp2017/.local/lib/python3.5/site-packages/tensorflow/python/framework/ops.py in set_shapes_for_outputs(op) 
    1755  shape_func = _call_cpp_shape_fn_and_require_op 
    1756 
-> 1757 shapes = shape_func(op) 
    1758 if shapes is None: 
    1759  raise RuntimeError(

/home/deepnlp2017/.local/lib/python3.5/site-packages/tensorflow/python/framework/ops.py in call_with_requiring(op) 
    1705 
    1706 def call_with_requiring(op): 
-> 1707  return call_cpp_shape_fn(op, require_shape_fn=True) 
    1708 
    1709 _call_cpp_shape_fn_and_require_op = call_with_requiring 

/home/deepnlp2017/.local/lib/python3.5/site-packages/tensorflow/python/framework/common_shapes.py in call_cpp_shape_fn(op, input_tensors_needed, input_tensors_as_shapes_needed, debug_python_shape_fn, require_shape_fn) 
    608  res = _call_cpp_shape_fn_impl(op, input_tensors_needed, 
    609         input_tensors_as_shapes_needed, 
--> 610         debug_python_shape_fn, require_shape_fn) 
    611  if not isinstance(res, dict): 
    612  # Handles the case where _call_cpp_shape_fn_impl calls unknown_shape(op). 

/home/deepnlp2017/.local/lib/python3.5/site-packages/tensorflow/python/framework/common_shapes.py in _call_cpp_shape_fn_impl(op, input_tensors_needed, input_tensors_as_shapes_needed, debug_python_shape_fn, require_shape_fn) 
    673  missing_shape_fn = True 
    674  else: 
--> 675  raise ValueError(err.message) 
    676 
    677 if missing_shape_fn: 

ValueError: Dimensions must be equal, but are 50 and 100 for 'rnn/while/basic_lstm_cell/mul' (op: 'Mul') with input shapes: [32,50], [32,100]. 

Answer 1

您應該考慮給出錯誤跟蹤。否則，很難（或不可能）提供幫助。

我轉載了這個情況，發現這個問題來自狀態解包，即行c, h = state。

嘗試設置state_is_tuple爲假，即

cell = tf.contrib.rnn.BasicLSTMCell(state_size, state_is_tuple=False) 

我不知道爲什麼會這樣。你正在加載以前的模型？什麼是您的tensorflow版本？

---

上TensorFlow RNN細胞的更多信息：

我建議你看一看：WildML post，部分 「RNN細胞，包裝和多層RNNS」。

它指出：

• BasicRNNCell – A vanilla RNN cell.
• GRUCell – A Gated Recurrent Unit cell.
• BasicLSTMCell – An LSTM cell based on Recurrent Neural Network Regularization. No peephole connection or cell clipping.
• LSTMCell – A more complex LSTM cell that allows for optional peephole connections and cell clipping.
• MultiRNNCell – A wrapper to combine multiple cells into a multi-layer cell.
• DropoutWrapper – A wrapper to add dropout to input and/or output connections of a cell.

鑑於此，我建議你改用從BasicRNNCell到BasicLSTMCell。這裏的Basic意思是「使用它，除非你知道你在做什麼」。如果你想嘗試 LSTMs沒有進入細節，多數民衆贊成在路上。它可能很簡單，只需要替換它就可以了！

如果不是，請分享您的部分代碼+錯誤。 「

希望它有幫助