我有大约10000个时间序列。
我想使用auto.arima函数http://www.inside-r.org/packages/cran/forecast/docs/auto.arima
我想测试我的auto.arima模型对于10000时间序列的准确性。我正在推迟20%的数据点(如果你看到40个样本中的8个),然后让auto.arima预测。然后,我可以比较生成的8个值和实际的8个值。
但是,在ARIMA模型中是否有一种正式的方法来检验精度呢?我的方法是correcT吗?
y=auto.arima(x)
plot(forecast(y,h=8))样本时间序列1
0.0003748,0.0003929,0.0003653,0.0003557,0.0004463,0.000349,0.0003099,0.0003395,0.0003157,0.0002871,0.0002604,0.0002422,0.0001917,0.0002117,0.0002689时间序列2
0.0003977,0.0003481,0.0002413,0.0002069,0.0002127,0.0002108,0.0002003,0.0002174,0.0002098,0.0002069,0.0001955,0.0001926,0.0002108,0.0002146,0.0002079发布于 2015-09-29 22:25:14
在我看来,你的Q是关于比较预测精度的不同指标,而不仅仅是auto.arima()和forecast()的具体使用。如果是这样的话,那么就有许多度量可以使用。有关概述,请参见
它们中的每一个都有其支持者和反对者;例如,见本文:
http://robjhyndman.com/papers/mase.pdf
不管你使用的是什么精确的度量,你仍然需要能够证明为什么你要隐瞒20%的数据用于预测。
但是,如果您对不同的模型形式感兴趣,那么您也有一些选项。例如,正如评论中所建议的,
arima() (或某些等价的)将相同的单变量模型(先验地)拟合到每个时间序列;auto.arima()对每个时间序列拟合(可能)不同的单变量模型;或如果您感兴趣的是#3,我建议您在这里使用MARSS pkg:
https://cran.r-project.org/web/packages/MARSS/index.html
以及这里的用户指南:
https://cran.r-project.org/web/packages/MARSS/vignettes/UserGuide.pdf
https://stackoverflow.com/questions/32847384
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