Bar Graphs

    

Representing Data using Bar Graph



Bar Graph    

A bar graph is a way of representing data with the help of rectangular bars.

A bar graph is a visual representation of data, it is usually more easier and quicker to understand than looking at the numerical data in tables. 

A bar graph with horizontal bars is referred as horizontal bar graph and a bar graph with vertical bars is referred as vertical bar graph.

An example data table given below, shows the number of points scored by the five teams.



Representing this data using Horizontal Bar Graph 


In a horizontal bar graph the bars are drawn horizontally.

A bar graph has two axis, one axis shows the categories and the other axis shows the values.


To represent this data as a horizontal bar graph, the categories that is teams in this example, are shown on vertical axis, and the horizontal axis will represent the number of points.


In this example the data varies from 15 to 25, a scale with increments of 5 as shown in the image below is suitable for the horizontal axis. The scale should be such that the data values can be represented nicely within the graph.


Team A has 15 points. The length of horizontal bar corresponds to 15 points on the horizontal axis.

Team B has 20 points. The length of horizontal bar corresponds to 20 points on the horizontal axis.



Team C has 15 points. The length of horizontal bar corresponds to 15 points on the horizontal axis.

Similarly the Horizontal bar for Team D corresponds to 25 points and the horizontal bar for Team E corresponds to 20 points.

A suitable title should be given to the graph.

This horizontal bar graph represents the data in the example.





Representing this data using Vertical Bar Graph

To represent the same data as a vertical bar graph, the teams are represented on horizontal axis, and the points of each team are represented on the vertical axis as shown below.

In a vertical bar graph the bars are drawn vertically.


In the image above same data is represented as in a vertical bar graph.


Team A has 15 points. The length of vertical bar corresponds to 15 points on the vertical axis.

Team B has 20 points. The length of vertical bar corresponds to 20 points on the vertical axis.

Team C has 15 points. The length of vertical bar corresponds to 15 points on the vertical axis.

Similarly the vertical bar for Team D corresponds to 25 points and the vertical bar for Team E corresponds to 20 points.