如何在Python中获得2个数据帧的减法平均值?
我有两个python数据帧 y如何在Python中获得2个数据帧的减法平均值?,python,pandas,dataframe,Python,Pandas,Dataframe,我有两个python数据帧 y 2015-06-05 15:00:00.000 20.22 2015-06-05 15:00:00.500 20.22 2015-06-05 15:00:01.000 20.22 ... 2015-06-05 15:31:38.500 114.95 2015-06-05 15:31:39.000 114.95 2015-06-05 15:31:39.500 114
2015-06-05 15:00:00.000 20.22
2015-06-05 15:00:00.500 20.22
2015-06-05 15:00:01.000 20.22
...
2015-06-05 15:31:38.500 114.95
2015-06-05 15:31:39.000 114.95
2015-06-05 15:31:39.500 114.95
Freq: 500L, Name: sensor_19, dtype: float64
y\u预测
2015-06-05 15:00:00.000 93.445314
2015-06-05 15:00:00.500 20.224281
2015-06-05 15:00:01.000 20.226055
...
2015-06-05 15:31:38.500 115.612101
2015-06-05 15:31:39.000 114.682510
2015-06-05 15:31:39.500 114.917647
Freq: 500L, dtype: float64
实际上,y\u predict是由ARMA模型计算的y的预测值。如您所见,它们具有相同的数据结构、相同的行数和相同的索引。然而,当我试图得到这两个数据帧的减法平均值时,我得到了一个错误
def mean_forecast_err(y, y_predict):
return y.sub(y_predict).mean()
# other preparation before ...
y = df['sensor_19']
arma_mod12 = sm.tsa.ARMA(y, (1, 2)).fit()
y_predict12 = arma_mod12.predict()
print "ARMA(1, 2): err_mean=" + mean_forecast_err(y, y_predict12)
我的问题是:
- 错误来自哪里
- 或者如何生成一个受欢迎的异常,以便我可以看到错误消息进行调试
def mean_forecast_err(y, y_predict):
return y.sub(y_predict).mean()
# other preparation before ...
y = df['sensor_19']
arma_mod12 = sm.tsa.ARMA(y, (1, 2)).fit()
y_predict12 = arma_mod12.predict()
print "ARMA(1, 2): err_mean=" + str(mean_forecast_err(y, y_predict12))