python、sklearn实现计算均方误差（MSE）、平均绝对误差（MAE）、决定系数（R2）、调整后的决定系数、皮尔逊相关系数

from sklearn.metrics import mean_squared_error # 均方误差
from sklearn.metrics import mean_absolute_error # 平方绝对误差
from sklearn.metrics import r2_score # R square
# 调整后的R square
def adj_r_squared(x_test,y_test,y_predict):
    SS_R = sum((y_test-y_predict)**2)
    SS_T = sum((y_test-np.mean(y_test))**2)
    r_squared = 1 - (float(SS_R))/SS_T
    adj_r_squared = 1 - (1-r_squared)*(len(y_test)-1)/(len(y_test)-x_test.shape[1]-1)
    return adj_r_squared
# 皮尔逊相关系数
from scipy.stats import pearsonr
#调用
mean_squared_error(y_test,y_predict)
mean_absolute_error(y_test,y_predict)
r2_score(y_test,y_predict)
adj_r_squared(x_test,y_test,y_predict)
pearsonr(y_test,y_predict)