Column Graphs

A column graph refers to the pictorial representation of numerical data. That can be in the form of bars or rectangles of equal width but varying heights. It is also called the bar graph. The rectangles of column graphs are drawn either vertically or horizontally. Moreover, the space between them is kept equal. The length or height of the rectangle depends on the numerical value represented by the same. Column graphs present categorical data with the help of rectangular bars. The heights and lengths of these bars are proportional to the values represented by them. You can plot the bars either horizontally or vertically.

How to Draw Column Graphs or Bar Graphs?

You are always given some numerical data, which you must represent in the form of graphs on graph paper. Now, we can make column graphs or bar graphs by following the below steps:

Step 1

Draw a horizontal line XY and a vertical line XZ on graph paper. We term these lines as the x-axis and y-axis, respectively.

Step 2

Next, mark the points at equal intervals on the x-axis. Write the names of the data items below these points whose values are supposed to be plotted.

Step 3

Next, you must choose a suitable scale. Then, determine the heights of the bars for the given values on that scale.

Step 4

Now, from the points taken in the second step, mark off the heights that are parallel to the y-axis.

Step 5

Lastly, draw the bars of equal length for all the heights marked in the fourth step. All of them should be centred on the points marked on the x-axis. These are the bars that represent the numerical data.

Properties of Column Graphs

There are some properties that make column graphs or bar graphs unique. We have listed the properties below:

1. The rectangular bars must have equal width and equal space between each other.
2. You can draw these bars either horizontally or vertically.
3. The height of any rectangular bar is equivalent to the data represented by it.
4. All the rectangular bars are supposed to be on a common base.

Uses of Column Graphs

Column graphs or bar graphs are mostly used in statistics and mathematics. Given below are some of the common uses of these graphs.

1. It makes the comparison of different variables convenient and easy.
2. It is one of the easiest diagrams to prepare, which doesn’t require much effort.
3. Column graphs are one of the most widely used methods of data representation. As a result, numerous industries use the same for various purposes.
4. It is further used to compare data sets. These are independent of each other.
5. It helps to study patterns over a long period of time.

Types of Column Graphs

Column graphs are classified into two types:

• Vertical bar graph
• Horizontal bar graph

You can plot the bars in column graphs either vertically or horizontally. However, the one that is most used is the vertical bar graph. Apart from these two graphs, there are two more types of column graphs. They are:

• Grouped bar graph
• Stacked bar graph

Vertical Bar Graph

When any given data is represented vertically in a chart or a graph, it is called a vertical graph. It is always made with the help of rectangular bars to show the measure of data. These bars are vertically drawn on the x-axis. On the other hand, the y-axis displays the value of the height of the same bars that represent the quantity of the variables earlier written on the x-axis.

Horizontal Bar Graph

When any given data is represented horizontally in a chart or a graph, it is called a horizontal graph. It is also made with the help of rectangular bars to show the measure of data. In this type of graph, the categories of data or variables must be written. Later, the rectangular bars are drawn horizontally on the y-axis. Meanwhile, the x-axis shows the length of these bars that is equal to the values of the various variables present in the data.

Stacked Bar Graph

The stacked bar graph is also known as the composite bar graph. It divides the entire bar into different parts. Each part of the said bar is represented using distinct colours. That is done to identify all the categories easily. Moreover, specific labelling is required to indicate the various parts of the bar. Thus, every rectangular bar represents the whole in a stacked bar graph. Moreover, each segment of the same bar shows the different parts of the whole. It can be displayed in a vertical form or horizontally.

Grouped Bar Graph

The grouped bar graph is also known as the clustered bar graph. It is used for displaying the discrete value of two or more categorical data. In a grouped bar graph, the rectangular bars are grouped according to positions for the levels of a single categorical variable. Moreover, the same colours show the secondary categorical level within each group. Just like the stacked bar graph, it can be shown either vertically or horizontally.

Conclusion

Column graphs or bar graphs are an integral part of both mathematics and statistics. These pictorial representations help us understand numerical data better. The above study material notes on column graphs are sure to help you understand the basics of these charts. If the frequency of data is large, it is always advisable to use column graphs. That is because they are convenient and easy to make within a short period of time. However, one thing that should be kept in mind is that there should be equal spacing between the bars used in these graphs. Also known as bar charts, column graphs can be represented both vertically and horizontally.