from sklearn import datasets # 數據集
from sklearn.model_selection import train_test_split from sklearn import linear_model import matplotlib.pyplot as plt
boston = datasets.load_boston() # 波士頓房價數據
boston

# 創建訓練集 與 測試集
x_train,x_test,y_train,y_test = train_test_split(boston.data,boston.target,test_size=0.1,random_state=42) print(x_train.shape,x_test.shape,y_train.shape,y_test.shape)
# 訓練數據
linreg = linear_model.LinearRegression()
linreg.fit(x_train, y_train)
# 得出預測值
y_pred = linreg.predict(x_test)
y_pred

plt.figure(figsize=(10,6)) # 設置大小
plt.plot(y_test,linewidth=3,label='Actual') plt.plot(y_pred,linewidth=3,label='Prediction') # 顯示上面設置的名字與底部
plt.legend(loc='best') plt.xlabel('test data point') plt.ylabel('target value')

plt.plot(y_test,y_pred,'o')
plt.plot([-10,60],[-10,60],'k--')
plt.axis([-10,60,-10,60])
plt.xlabel('Actual')
plt.ylabel('Prediction')
