Here we will discuss the graphical representation of time series data, called historigram.

As we have discussed in the introduction to Time Series Data, given an observed time series, the first step in analyzing a time series is to plot the given series on a graph taking time intervals ($t$) along X-axis (as an independent variable) and the observed value ($Y_t$) on Y-axis (as the dependent variable: as a function of time). Such a graph will show various types of fluctuations and other points of interest.

A historigram is a graphical representation of a time series that reveals the changes that occurred at different time periods. A first step in the prediction (or forecast) of a time series involves an examination of the set of past observations. In this case, historigram may be a useful tool. The construction of a historigram involves the following steps described below:

  • Use an appropriate scale and take time $t$ along $x$-axis as an independent variable.
  • Use an appropriate scale, plot the observed values of variable $Y$ as a dependent variable against the given points of time.
  • Join the plotted points by line segments to get the required graphical representation.

Example: Draw a historigram to show the population of Pakistan in various census years.

Census Year195119611972198119982017
Population (Million33.4442.8865.3183.78130.58200.17

Muhammad Imdad Ullah

Currently working as Assistant Professor of Statistics in Ghazi University, Dera Ghazi Khan. Completed my Ph.D. in Statistics from the Department of Statistics, Bahauddin Zakariya University, Multan, Pakistan. l like Applied Statistics, Mathematics, and Statistical Computing. Statistical and Mathematical software used is SAS, STATA, GRETL, EVIEWS, R, SPSS, VBA in MS-Excel. Like to use type-setting LaTeX for composing Articles, thesis, etc.

You may also like...

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

x Logo: Shield Security
This Site Is Protected By
Shield Security