Python tf.keras.models.clone_model未知激活：ReLU

环境是Python 3.7.6，下面是我的导入：

import os, sys
import tensorflow as tf    # v2.2.0
tf.compat.v1.enable_eager_execution()
import numpy as np
import matplotlib.pyplot as plt
from sys import platform
import time
import random
import pickle
from tensorflow.keras.layers import ReLU

我试图克隆一个tf.keras.Model但没有成功，因为ReLU是一个未知的激活。然而，启动是成功的，因此系统应该知道什么是ReLU。我想知道如何解决这个问题

def init_model(D=8, W=256):
    # This is a simple MLP neural network
    # D: The number of layers
    # H: The neurons in each layer
    relu = ReLU()
    dense = lambda W=W, act=relu: tf.keras.layers.Dense(W, activation=act, dtype='float32')

    inputs = tf.keras.Input(shape=(3 + 3 * 2 * L_embed))
    outputs = inputs
    for i in range(D):
        outputs = dense()(outputs)
        if i % 4 == 0 and i > 0:
            outputs = tf.concat([outputs, inputs], -1)
    outputs = dense(4, act=None)(outputs)

    model = tf.keras.Model(inputs=inputs, outputs=outputs)
    return model

然后我打电话：

model_inner_copy = tf.keras.models.clone_model(model)

错误消息是：

  File "D:/Code Repository/Meta-NeRF/Code/NeRF/Tiny_MAML_NeRF.py", line 211, in train_maml_nerf
    model_inner_copy = tf.keras.models.clone_model(model)

  File "C:\Users\Jack\AppData\Roaming\Python\Python37\site-packages\tensorflow\python\keras\models.py", line 427, in clone_model
    model, input_tensors=input_tensors, layer_fn=clone_function)

  File "C:\Users\Jack\AppData\Roaming\Python\Python37\site-packages\tensorflow\python\keras\models.py", line 196, in _clone_functional_model
    model, new_input_layers, layer_fn)

  File "C:\Users\Jack\AppData\Roaming\Python\Python37\site-packages\tensorflow\python\keras\models.py", line 246, in _clone_layers_and_model_config
    config = network.get_network_config(model, serialize_layer_fn=_copy_layer)

File "C:\Users\Jack\AppData\Roaming\Python\Python37\site-packages\tensorflow\python\keras\engine\network.py", line 2119, in get_network_config
    layer_config = serialize_layer_fn(layer)

  File "C:\Users\Jack\AppData\Roaming\Python\Python37\site-packages\tensorflow\python\keras\models.py", line 243, in _copy_layer
    created_layers[layer.name] = layer_fn(layer)

File "C:\Users\Jack\AppData\Roaming\Python\Python37\site-packages\tensorflow\python\keras\models.py", line 61, in _clone_layer
    return layer.__class__.from_config(layer.get_config())

File "C:\Users\Jack\AppData\Roaming\Python\Python37\site-packages\tensorflow\python\keras\engine\base_layer.py", line 655, in from_config
    return cls(**config)

File "C:\Users\Jack\AppData\Roaming\Python\Python37\site-packages\tensorflow\python\keras\layers\core.py", line 1135, in __init__
    self.activation = activations.get(activation)

File "C:\Users\Jack\AppData\Roaming\Python\Python37\site-packages\tensorflow\python\keras\activations.py", line 465, in get
    identifier, printable_module_name='activation')

File "C:\Users\Jack\AppData\Roaming\Python\Python37\site-packages\tensorflow\python\keras\utils\generic_utils.py", line 362, in deserialize_keras_object
    config, module_objects, custom_objects, printable_module_name)

File "C:\Users\Jack\AppData\Roaming\Python\Python37\site-packages\tensorflow\python\keras\utils\generic_utils.py", line 321, in class_and_config_for_serialized_keras_object
    raise ValueError('Unknown ' + printable_module_name + ': ' + class_name)
ValueError: Unknown activation: ReLU

---

所以问题是

tf.keras.layers.ReLU

是一个实现ReLU激活的层，但它本身不是一个激活函数。它将用作模型内部的层，而不是

密集层的参数

要使一个函数作为激活，作为参数提供给
Dense
，您应该使用
tf.keras.activations.relu
请将导入添加到现在添加的代码中。谢谢你的提醒。