- Stationarity
- It refers to the data that exhibits a consistent statistical distribution over time.
- Differencing
- This is a technique used to make a non-stationary data stationary.
- Involves taking the difference between consecutive observations to remove the trend or seasonality.
- Time interval
- The fixed amount of time between each observation in a time series. It can be same for the inputs and ouputs or a specific time interval for inputs and different time interval of ouput.
- I have handled data where Inputs were taken between 1 hour and the ouputs were found between 15mins so that there are 4 outputs in just 1 hour.
- Timestamp
- The specific time at which an observation is recorded.
- This is usually converted into sine and cosine encoding to make the model understand that this is variation of time.
- Seasonality
- A regular pattern of changes in a time series that occurs at fixed intervals of time.
- Autocorrelation
- The degree to which a time series is correlated with its own lagged values.
- Lag
- The amount of time between two observations in a time series.
- Smoothing
- The process of removing noise and other short term fluctuations from a time series to reveal its underlying trends and seasonality.
- Trend
- The long term pattern or direction in a time series.
References:
- Informer: Beyond Efficient Transformer for Long Sequence Time-Series Forecasting
- Multivariate Time Series Forecasting with Transformers
- This includes the implementation of spacetimeformer.