What is Time Series?

What is a Time Series?

• Time Series data is a series of data points indexed or listed or graphed with an equally spaced period.
• Time series forecasting is the use of the model to predict future values based on previously observed value.
• Input Past --> Predict future.

Component of Time Series:

• Trend: Increase or decrease over a long period. India GDP
• Seasonal Pattern: Short-term variation occurring due to seasonal factors. Winter sales
• Cyclical Patterns: It is a medium-term variation caused by circumstances, which repeat in irregular intervals. Recession
• Irregularity Patterns: Which Occurs due to unpredictable factors. Anomaly

Where can we not use Time Series?

• If the variable is not dependent on time.
• If Values are constant.
• Values represented using known function as sin(x), cos(x) etc.
• Time Series algorithm cannot be used if data is not stationary.

Time series models:

• ARIMA
• SARIMA
• FARIMA
• LSTM