Tensorflow2 Keras 调整单位和激活函数

问题描述

我正在尝试设置一个 Keras 调谐器来同时调整层数和激活函数。网络试图将一个 2D 函数变形为另一个 2D 函数。我不断收到错误：

ValueError: UnkNown activation function: sigmoidtanh

我的代码如下：

python

def euclidean_distance_loss(y_true,y_pred):
return tf.reduce_sum(tf.math.squared_difference(y_pred,y_true),axis=1)

def model_builder(hp):
model = tf.keras.Sequential()
tf.keras.layers.InputLayer(input_shape=(2,)),#===Tune number of layers===#
for i in range(hp.Int('num_layers',2,5)):
    #===Tune number of units and activation in each layer===#
    hp_units = hp.Int('units_' + str(i),min_value=12,max_value=512,step=10)
    activation = hp.Choice('activation_' + str(i),['linear','relu','selu','sigmoid','tanh'])
    model.add(tf.keras.layers.Dense(units=hp_units,activation=activation))

#===Add Final Layer===#
model.add(tf.keras.layers.Dense(units=2,activation='linear'))

#===Compile===#
model.compile(optimizer='adam',loss=euclidean_distance_loss,metrics=['MeanSquaredError'])

return model

b_tuner = Bayesianoptimization( model_builder,objective = 'val_mean_squared_error',max_trials = 10,executions_per_trial = 15,directory = 'output',project_name = 'b_tune_nn' )


b_tuner.search(x_train_points,y_train_points,epochs=25,validation_split=0.2)

现在如果我写：

    model.add(tf.keras.layers.Dense(units=hp_units,activation='tanh'))

一切正常。我在指定模型时做错了什么？

如果您需要更多上下文，请告诉我。

解决方法

对我有用的完整代码：

import kerastuner as kt
import tensorflow as tf
from kerastuner import BayesianOptimization
import numpy as np

x_train = np.random.randn(1000,20)
y_train = np.random.randn(1000,2)

def euclidean_distance_loss(y_true,y_pred):
  return tf.reduce_sum(tf.math.squared_difference(y_pred,y_true),axis=1)

def model_builder(hp):
  model = tf.keras.Sequential()
  tf.keras.layers.InputLayer(input_shape=(2,)),#===Tune number of layers===#
  for i in range(hp.Int('num_layers',2,5)):
    #===Tune number of units and activation in each layer===#
    hp_units = hp.Int('units_' + str(i),min_value=12,max_value=512,step=10)
    activation = hp.Choice('activation_' + str(i),['linear','relu','selu','sigmoid','tanh'])
    model.add(tf.keras.layers.Dense(units=hp_units,activation=activation))
  #===Add Final Layer===#
  model.add(tf.keras.layers.Dense(units=2,activation='linear'))

  #===Compile===#
  model.compile(optimizer='adam',loss=euclidean_distance_loss,metrics=['MeanSquaredError'])

  return model


b_tuner = BayesianOptimization( model_builder,objective = 'val_mean_squared_error',max_trials = 10,executions_per_trial = 15,directory = 'output',project_name = 'b_tune_nn' )


b_tuner.search(x_train,y_train,epochs=25,validation_split=0.2)

编辑：

pip uninstall keras-tuner
pip install -U keras-tuner # get the latest version