I want to extract the seasonality from my sarima model.
My dataset is in the format of this:
ds: dates
y: metric
This is weekly data
I have done the following:
<code>ts_data <- ts(for_seasonality$y, frequency = 52, start = c(year(start_date), 1 + for_seasonality$week_num[1]))
sarima_model <- auto.arima(ts_data, seasonal = TRUE)
summary(sarima_model)
Series: ts_data
ARIMA(0,1,2)(2,0,1)[52] with drift
Coefficients:
ma1 ma2 sar1 sar2 sma1 drift
-0.4227 -0.1011 0.2145 0.1747 0.1393 0.0006
s.e. 0.0510 0.0558 0.5443 0.2208 0.5584 0.0023
sigma^2 = 0.003411: log likelihood = 533.48
AIC=-1052.95 AICc=-1052.65 BIC=-1025.43
Training set error measures:
ME RMSE MAE MPE MAPE MASE ACF1
Training set 0.0002524145 0.05785966 0.03492112 -Inf Inf 0.3350916 0.0122546
</code>
<code>ts_data <- ts(for_seasonality$y, frequency = 52, start = c(year(start_date), 1 + for_seasonality$week_num[1]))
sarima_model <- auto.arima(ts_data, seasonal = TRUE)
summary(sarima_model)
Series: ts_data
ARIMA(0,1,2)(2,0,1)[52] with drift
Coefficients:
ma1 ma2 sar1 sar2 sma1 drift
-0.4227 -0.1011 0.2145 0.1747 0.1393 0.0006
s.e. 0.0510 0.0558 0.5443 0.2208 0.5584 0.0023
sigma^2 = 0.003411: log likelihood = 533.48
AIC=-1052.95 AICc=-1052.65 BIC=-1025.43
Training set error measures:
ME RMSE MAE MPE MAPE MASE ACF1
Training set 0.0002524145 0.05785966 0.03492112 -Inf Inf 0.3350916 0.0122546
</code>
ts_data <- ts(for_seasonality$y, frequency = 52, start = c(year(start_date), 1 + for_seasonality$week_num[1]))
sarima_model <- auto.arima(ts_data, seasonal = TRUE)
summary(sarima_model)
Series: ts_data
ARIMA(0,1,2)(2,0,1)[52] with drift
Coefficients:
ma1 ma2 sar1 sar2 sma1 drift
-0.4227 -0.1011 0.2145 0.1747 0.1393 0.0006
s.e. 0.0510 0.0558 0.5443 0.2208 0.5584 0.0023
sigma^2 = 0.003411: log likelihood = 533.48
AIC=-1052.95 AICc=-1052.65 BIC=-1025.43
Training set error measures:
ME RMSE MAE MPE MAPE MASE ACF1
Training set 0.0002524145 0.05785966 0.03492112 -Inf Inf 0.3350916 0.0122546
How do I extract the seasonality directly from the model instead of using stl or decompose? Is it even possible?