fable

问题 I have a time series that looks like this t value 1 12 2 12 3 0 4 0 5 0 6 0 7 0 I expect acf1 to equal 0.443, but instead the accuracy function produces null. The code is as following: df = data.frame("t" = 1:7, "value" = c(12, 12, 0, 0, 0, 0, 0)) tsb = df %>% as_tsibble(index = t) md = tsb %>% model(arima = ARIMA(value ~ PDQ(period = 4), stepwise = F)) fc = md %>% forecast(h = 4) accuracy(fc, tsb) Why is this happening? 回答1: The ACF1 column from accuracy() is the first auto-correlation of

来源： https://stackoverflow.com/questions/64339451/why-in-fable-forecast-libraries-residual-diagnostics-of-arima-models-is-done-wit