自定义张量流模型上的 InvalidArgumentError

Question

作为TPS July challenge 的一部分，我试图实现一个基于循环神经网络的自定义张量流模型

想法： 我想包含一个 RNN，它根据模型在上一次迭代中的预测来预测当前迭代中的值。因此，我实现了一个自定义模型，它保存了当前迭代的输出，以便在下一次迭代中馈送到模型的 LSTM 层。

但是，如果我调用模型的 fit 方法，则会出现以下错误

InvalidArgumentError                      Traceback (most recent call last)
<ipython-input-29-0457da000b62> in <module>
----> 1 model.fit(train_x,train_labels,epochs=100)

/opt/conda/lib/python3.7/site-packages/tensorflow/python/keras/engine/training.py in fit(self, x, y, batch_size, epochs, verbose, callbacks, validation_split, validation_data, shuffle, class_weight, sample_weight, initial_epoch, steps_per_epoch, validation_steps, validation_batch_size, validation_freq, max_queue_size, workers, use_multiprocessing)
   1098                 _r=1):
   1099               callbacks.on_train_batch_begin(step)
-> 1100               tmp_logs = self.train_function(iterator)
   1101               if data_handler.should_sync:
   1102                 context.async_wait()

/opt/conda/lib/python3.7/site-packages/tensorflow/python/eager/def_function.py in __call__(self, *args, **kwds)
    826     tracing_count = self.experimental_get_tracing_count()
    827     with trace.Trace(self._name) as tm:
--> 828       result = self._call(*args, **kwds)
    829       compiler = "xla" if self._experimental_compile else "nonXla"
    830       new_tracing_count = self.experimental_get_tracing_count()

/opt/conda/lib/python3.7/site-packages/tensorflow/python/eager/def_function.py in _call(self, *args, **kwds)
    886         # Lifting succeeded, so variables are initialized and we can run the
    887         # stateless function.
--> 888         return self._stateless_fn(*args, **kwds)
    889     else:
    890       _, _, _, filtered_flat_args = \

/opt/conda/lib/python3.7/site-packages/tensorflow/python/eager/function.py in __call__(self, *args, **kwargs)
   2941        filtered_flat_args) = self._maybe_define_function(args, kwargs)
   2942     return graph_function._call_flat(
-> 2943         filtered_flat_args, captured_inputs=graph_function.captured_inputs)  # pylint: disable=protected-access
   2944 
   2945   @property

/opt/conda/lib/python3.7/site-packages/tensorflow/python/eager/function.py in _call_flat(self, args, captured_inputs, cancellation_manager)
   1917       # No tape is watching; skip to running the function.
   1918       return self._build_call_outputs(self._inference_function.call(
-> 1919           ctx, args, cancellation_manager=cancellation_manager))
   1920     forward_backward = self._select_forward_and_backward_functions(
   1921         args,

/opt/conda/lib/python3.7/site-packages/tensorflow/python/eager/function.py in call(self, ctx, args, cancellation_manager)
    558               inputs=args,
    559               attrs=attrs,
--> 560               ctx=ctx)
    561         else:
    562           outputs = execute.execute_with_cancellation(

/opt/conda/lib/python3.7/site-packages/tensorflow/python/eager/execute.py in quick_execute(op_name, num_outputs, inputs, attrs, ctx, name)
     58     ctx.ensure_initialized()
     59     tensors = pywrap_tfe.TFE_Py_Execute(ctx._handle, device_name, op_name,
---> 60                                         inputs, attrs, num_outputs)
     61   except core._NotOkStatusException as e:
     62     if name is not None:

InvalidArgumentError:  Can not squeeze dim[0], expected a dimension of 1, got 32
     [[{{node lstm_model/weight_normalization_15/cond/else/_1/lstm_model/weight_normalization_15/cond/data_dep_init/moments/Squeeze}}]] [Op:__inference_train_function_11775]

Function call stack:
train_function

我使用模型的方法正确吗？如果不是，我的想法的更好实施方式是什么？

我的代码：

import tensorflow as tf
from tensorflow import keras
from tensorflow.keras import layers
import tensorflow_addons as tfa

train_labels = train_data[['target_carbon_monoxide','target_benzene','target_nitrogen_oxides']].copy()
train_x = train_data.drop(['target_carbon_monoxide','target_benzene','target_nitrogen_oxides','date_time'],axis=1)
train_x.head()
train_labels = np.asarray(train_labels).reshape(-1,1,3)


curroutput = tf.Variable(shape=(1,3),initial_value=[[0.0,0.0,0.0]],dtype=tf.float32)
class CompleteModel(keras.Model):
    def train_step(self, data):
        x,y = data
#         x = tf.reshape(self.curroutput,shape=(1,1,3))
        
        with tf.GradientTape() as tape:
            y_pred = self(x, training=True)
            loss = self.compiled_loss(y_pred,y, regularization_losses=self.losses)

        global curroutput
        curroutput.assign(y_pred)
        trainable_vars = self.trainable_variables
        gradients = tape.gradient(loss, trainable_vars)
        self.optimizer.apply_gradients(zip(gradients, trainable_vars))
        self.compiled_metrics.update_state(y, y_pred)
        return {m.name: m.result() for m in self.metrics}



class RNNInputLayer(keras.layers.Layer):
    def __init__(self):
        super(RNNInputLayer,self).__init__()
    def call(self,inputs):
        global curroutput
        return tf.reshape(curroutput,shape=(1,1,3))



def make_model():
    input_layer = layers.Input(shape=8,batch_size=1)
    dense_in = tfa.layers.WeightNormalization(layers.Dense(16,activation='selu'))(input_layer)
    dense_in2 = tfa.layers.WeightNormalization(layers.Dense(32,activation='selu'))(dense_in)
    dense_out = tfa.layers.WeightNormalization(layers.Dense(8,activation='selu'))(dense_in)
    rnn_input = RNNInputLayer()(input_layer)
    lstm_layer = layers.LSTM(units=16,input_shape=(1,3))(rnn_input)
    lstm_dense = tfa.layers.WeightNormalization(layers.Dense(16,activation='selu'))(lstm_layer)
    finalconcat = layers.Concatenate()([dense_out,lstm_dense])
    final_dense = tfa.layers.WeightNormalization(layers.Dense(16,activation='selu'))(finalconcat)
    output_layer = layers.Dense(3)(final_dense)

    model = CompleteModel(inputs=input_layer,outputs=output_layer,name='lstm_model')
    return model
model = make_model()
model.compile(loss=tf.keras.losses.MeanSquaredLogarithmicError(),optimizer='Adam')



model.fit(train_x,train_labels,epochs=100) #error

Answer 1

正如 Priya 强调的那样，错误表示 dim[0] 指的是批次维度，因此此答案可能无法解决您的错误，但它肯定会帮助您实现模型。

在您的 make_model() 函数中，尝试将 dense_out 更改为

dense_out = tfa.layers.WeightNormalization(layers.Dense(8,activation='selu'))(dense_in2)

在make_model() 函数中，您的dense_in2 层不用作dense_output 层的输入。您可能想在模型中使用这一层，却忘记将 2 添加到变量名称的末尾。此外，我会假设dense_output 层正在寻找 32 个神经元的输入维度，这可能是导致错误的原因（尽管这可能已通过实现 WeightNormalization 层对象的方式完全绕过）。