#!/usr/bin/python
# coding=utf-8
from sklearn.datasets import load_boston
from sklearn.model_selection import train_test_split
from sklearn.preprocessing import StandardScaler
from sklearn.linear_model import LinearRegression
from sklearn.linear_model import SGDRegressor
from sklearn.metrics import mean_squared_error
def liner1():
#线性回归的正规方程优化对波士顿房价进行预测
#获取数据
boston=load_boston()
print "\n", boston.data.shape
#数据划分
x_train, x_test, y_train, y_test = train_test_split(boston.data, boston.target, random_state=22)
#特征工程:标准化
transform = StandardScaler()
x_train = transform.fit_transform(x_train)
x_test = transform.transform(x_test)
#线性回归预估器
estimator = LinearRegression()
estimator.fit(x_train, y_train)
print "正规化方程系数:\n", estimator.coef_
print "正骨化偏重:\n", estimator.intercept_
#均方误差进行评估
y_predict = estimator.predict(x_test)
error = mean_squared_error(y_test, y_predict)
print "正规方程均方误差:\n", error
return None
def liner2():
#线性回归的梯度下降优化对波士顿房价进行预测
#获取数据
boston=load_boston()
print "\n", boston.data.shape
#数据划分
x_train, x_test, y_train, y_test = train_test_split(boston.data, boston.target, random_state=22)
#特征工程:标准化
transform = StandardScaler()
x_train = transform.fit_transform(x_train)
x_test = transform.transform(x_test)
#线性回归预估器
estimator = SGDRegressor()
estimator.fit(x_train, y_train)
print "正规化方程系数:\n", estimator.coef_
print "正骨化偏重:\n", estimator.intercept_
#模型评估
# 均方误差进行评估
y_predict = estimator.predict(x_test)
error = mean_squared_error(y_test, y_predict)
print "梯度下降均方误差:\n", error
return None
liner1()
liner2()