Time Series and Forecasting Time Series A time
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Time Series and Forecasting
Time Series A time series is a set of statistical observations arranged in chronological order. A time series is a collection of data recorded over a period of time - weekly, monthly, quarterly, or yearly.
Example of Time series Economics - weekly share prices, monthly profits Meteorology - daily rainfall, wind speed, temperature Sociology - crime figures (number of arrests, etc), employment figures
Utility of Time series analysis It helps in understanding past behaviour It helps in planning future operations It helps in evaluating current accomplishments It facilitates comparison
Components of time series Secular Trend Seasonal Variations Cyclical Variations Irregular Variations
Secular Trend is a long term movement in a time series. It is the underlying direction (upward or downward) and rate of change in a time series, when allowance has been made for the other components.
Understanding Secular Trend Basic tendency of production, sales, income, employment, etc. • Population Change • an aging population (which will tend to have different spending and savings habits than a younger population) • Technological Progress • the expansion of a particular technology (such as the Internet) • heavy reliance on certain commodities (like oil) • Large scale shift in customer tastes
Understanding Secular Trend Linear and nonlinear trend Definition of long period Long term movement
Secular trend in equity market
Measurement of secular trend Freehand smooth curve Semi-average method Moving average method Methods of least squares
Seasonal variations • Periodic movements in business activity which occur regularly every year and have their origin in the nature of the year itself. • Repeat during a period of 12 months
Factors causing seasonal variations Climate and whether conditions Customs, traditions, and habits
Cyclical variations of non-seasonal nature, whose periodicity is unknown. Changes of economy activity as a result of recurring causes.
Business Cycle
Business cycle Do not show regular periodicity Longer than one year (2 to 10 years) Different set of causes
Irregular Variations Irregular variations refer to such variations which do not repeat in a definite pattern. Also called erratic, accidental and random. Causes of such variations may be floods, earthquakes, strikes, wars, etc.
Components of a Time Series Additive Model • Y=T+C+S+R Multiplicative Model • Y=T×C×S×R
we denote the time series by Y, the secular trend by T, the seasonal movements by S, the long term cyclical movements by C and the irregular or residual component by R
Preliminary adjustments Calendar Variations Population changes Price changes Comparability
Measurement of Trend Freehand or Graphic Method Semi-average Method Moving average method Methods of Least Square
Practical 1 Year Sales ( in Rs. Lakhs) 2003 10 2004 13 2005 16 2006 21 2007 24
Practical 2 Year 1993 1994 1995 1996 1997 1998 1999 2000 No. of Industrial Failures 23 26 28 32 20 12 12 10
- Pendekatan dalam analisis time series
- Centered moving average example
- Time series forecasting
- Series aiding and series opposing
- Compare and contrast analog and digital forecasts.
- Compare and contrast analog and digital forecasting
- Maclaurin series vs taylor series
- Heisenberg 1925 paper
- Maclaurin series vs taylor series
- Taylor frederick
- P series server
- Feedback amplifier topologies
- Sum of infinite series
- Technology life cycle
- What is demand forecasting and estimation
- Demand estimation and forecasting
- Demand forecasting and replenishment
- Barometric methods are used to forecast
- Forecasting and demand measurement
- Forecasting and demand measurement in marketing
- Collaborative planning forecasting and replenishment ppt
- Financial planning and forecasting
- Financial planning and forecasting