Basic Statistics

The factors that are responsible for bringing about changes in a time series, also called the components of time series,… Click here to read more

The objective of the time series analysis is to identify the magnitude and direction of trends, to estimate the effect… Click here to read more

A number of different methods are available to estimate the trend; however, the suitability of these methods largely depends on… Click here to read more

This is a familiar concept, and is briefly described for drawing frequency curves. In case of a time series a… Click here to read more

Advantages This method is very simple and easy to understand. It is applicable to linear and non-linear trends. It gives… Click here to read more

This method is as simple and relatively objective as the free hand method. The data is divided in two equal… Click here to read more

Advantages This method is very simple and easy to understand, and also it does not require many calculations. Disadvantages The… Click here to read more

Suppose that there are $$n$$ time periods denoted by $${t_1},{t_2},{t_3}, \ldots ,{t_n}$$ and the corresponding values of the $$Y$$ variable… Click here to read more

Advantages Moving averages can be used for measuring the trend of any series. This method is applicable to linear as… Click here to read more

Using the multiplicative model, i.e.$$Y = T \times S \times R$$, the ratio detrended series may be obtained by dividing… Click here to read more

Using the additive model, i.e. $$Y = T + S + R$$, the de-trended series may be obtained by subtracting… Click here to read more

The long term cyclical movements in a time series can be studied more or less in the same way as… Click here to read more

Mathematical curve fitting is probably the most objective method of isolating trends. This method enables us to obtain precise estimates… Click here to read more