every blog every motto: Your happy passer-by all knows, my distressed there is no place hides.
0. 前言
wide & deep 模型 ,多输入问题 (函数式API)
1. 代码部分
1. 导入模块
import matplotlib as mpl
import matplotlib.pyplot as plt
%matplotlib inline
import numpy as np
import sklearn
import pandas as pd
import os
import sys
import time
import tensorflow as tf
from tensorflow import keras
print(tf.__version__)
print(sys.version_info)
for module in mpl,np,pd,sklearn,tf,keras:
print(module.__name__,module.__version__)
2. 读取数据
from sklearn.datasets import fetch_california_housing
# 房价预测
housing = fetch_california_housing()
print(housing.DESCR)
print(housing.data.shape)
print(housing.target.shape)
3. 划分样本
# 划分样本
from sklearn.model_selection import train_test_split
x_train_all,x_test,y_train_all,y_test = train_test_split(housing.data,housing.target,random_state=7)
x_train,x_valid,y_train,y_valid = train_test_split(x_train_all,y_train_all,random_state=11)
print(x_train.shape,y_train.shape)
print(x_valid.shape,y_valid.shape)
print(x_test.shape,y_test.shape)
4. 数据归一化
# 归一化
from sklearn.preprocessing import StandardScaler
scaler = StandardScaler()
x_train_scaled = scaler.fit_transform(x_train)
x_valid_scaled = scaler.transform(x_valid)
x_test_scaled = scaler.transform(x_test)
5. 多输入
# 多输入(函数式方法)
input_wide = keras.layers.Input(shape=[5])
input_deep = keras.layers.Input(shape=[6])
hidden1 = keras.layers.Dense(30,activation='relu')(input_deep)
hidden2 = keras.layers.Dense(30,activation='relu')(hidden1)
concat = keras.layers.concatenate([input_wide,hidden2])
output = keras.layers.Dense(1)(concat)
model = keras.models.Model(inputs=[input_wide,input_deep],outputs=[output])
6. 编译和回调函数
# 打印model信息
model.summary()
# 编译
model.compile(loss='mean_squared_error',optimizer="adam")
# 回调函数
callbacks = [keras.callbacks.EarlyStopping(patience=5,min_delta=1e-2)]
7. 训练
# 一共8个特征,wide前5个,deep后6个
x_train_scaled_wide = x_train_scaled[:,:5]
x_train_scaled_deep = x_train_scaled[:,2:]
x_valid_scaled_wide = x_valid_scaled[:,:5]
x_valid_scaled_deep = x_valid_scaled[:,2:]
x_test_scaled_wide = x_test_scaled[:,:5]
x_test_scaled_deep = x_test_scaled[:,2:]
#训练
history = model.fit([x_train_scaled_wide,x_train_scaled_deep],y_train,validation_data=([x_valid_scaled_wide,x_valid_scaled_deep],y_valid),epochs=100,callbacks=callbacks)
8. 学习曲线
# 学习曲线
def plot_learning_curves(history):
pd.DataFrame(history.history).plot(figsize=(8,5))
plt.grid(True)
plt.gca().set_ylim(0,1)
plt.show()
plot_learning_curves(history)
9. 测试集上
model.evaluate([x_test_scaled_wide,x_test_scaled_deep],y_test)