
The `FORECAST.ETS.STAT` function in Excel is used to return a specific statistic related to the forecast generated by the Exponential Smoothing (ETS) algorithm, which is commonly used for time series forecasting. Here’s how you can use this function:
Syntax
FORECAST.ETS.STAT(target_date, values, timeline, statistic_type[, seasonality, data_completion, aggregation])
Parameters
- `target_date`: The date for which you want to predict the value. This date should align with your timeline range.
- `values`: The historical values for which you want to forecast the statistics. This is your known data that corresponds to the timeline.
- `timeline`: The range that represents the timeline or dates associated with your historical data. This range should have a constant step between data points.
- `statistic_type`: The type of statistic you want to return. It is an integer value representing different statistics:
- 1: Alpha
- 2: Beta
- 3: Gamma
- 4: MSE (Mean Squared Error)
- 5: SMAPE (Symmetric Mean Absolute Percent Error)
- 6: MAE (Mean Absolute Error)
- 7: RMSE (Root Mean Squared Error)
- 8: Step size
- 9: Returned seasonality
- 10: Regressor count
- 11: R-squared
- 12: Forecast error
- `seasonality` (optional): A numerical value indicating the length of the seasonal pattern. By default, Excel will detect it automatically. If you do not want a seasonal pattern, set this to 0.
- `data_completion` (optional): This parameter specifies how to treat missing data:
- 0: Missing data is treated as zeros.
- 1: Missing data is averaged from neighboring points.
- Default is 1.
- `aggregation` (optional): Specifies how to aggregate data if you have duplicate timestamps:
- 1: AVERAGE
- 2: COUNT
- 3: COUNTA
- 4: MAX
- 5: MEDIAN
- 6: MIN
- 7: SUM
- Default is AVERAGE.
Example
Suppose you have a dataset with dates in column A (timeline) and sales in column B (values), and you want to calculate the Mean Squared Error (MSE) statistic for your ETS forecast. You would write:
=FORECAST.ETS.STAT(A2, B2:B50, A2:A50, 4)
Things to Keep in Mind
- Make sure your timeline has consistent intervals; otherwise, you might encounter errors or inaccurate forecasts.
- The data completion and aggregation parameters help in managing missing and redundant data, which can improve forecast accuracy.
Using `FORECAST.ETS.STAT`, you can analyze and refine your forecast by understanding key metrics like seasonality, trend, error margins, and more, which are vital for making informed business decisions.