看到这个月度数据:R:为什么当一个预测模型的MASE是NaN时呢?
tsdata <- structure(c(9.55584, 42.31872, 17.064, 54.26352, 79.51824, 44.3664,
82.58976, 129.6864, 70.64496, 102.384, 118.08288, 99.31248, 151.8696,
172.68768, 129.34512), .Tsp = c(2015.25, 2016.41666666667, 12
), class = "ts")
plot(tsdata)
然后,我分裂串联成培训和试台:
training <- structure(c(9.55584, 42.31872, 17.064, 54.26352, 79.51824, 44.3664,
82.58976, 129.6864, 70.64496, 102.384, 118.08288, 99.31248),
.Tsp = c(2015.25, 2016.16666666667, 12), class = "ts")
test <- structure(c(151.8696, 172.68768, 129.34512), .Tsp = c(2016.25, 2016.41666666667, 12), class = "ts")
最后,我适应tbats
模型和计算MASE值
require(forecast)
fit <- tbats(training)
fcast <- forecast(fit)
accuracy(fcast, test)
ME RMSE MAE MPE MAPE MASE ACF1 Theil's U
Training set -0.9012629 20.02206 16.33986 -22.70125 40.40976 NaN -0.3870826 NA
Test set 12.3136351 25.58155 24.77819 6.50544 16.14211 NaN -0.2992376 0.860442
你看到MASE无法计算。实际上,forecast
包中的所有其他型号也为MASE输出NaN。
为什么? MASE指标对我来说非常重要,我想用它来比较我的时间序列数据的几个模型。
我怀疑你的缩放数据太少 –