Line graph also known as a line chart or line plot is a tool used for data visualization . It is a type of graph that represents the data in a pictorial form which makes the raw data more easily understandable. In a line graph data points are connected with a straight-line and data points are represented either with points or wedges. Some other examples of graphs are bar graphs, histograms, pie charts, line graphs, etc.
A line graph or line chart is a graphical representation of the data that displays the relationship between two or more variables concerning time. It is made by connecting data points with straight-line segments.
Line Graph
Parts of Line Graph
Parts of the line graph include the following:
Title: It is nothing but the title of the graph drawn.
Axes: The line graph contains two axes i.e. X-axis and Y-axis.
Labels: The name given to the x-axis and y-axis.
Line: It is the line segment that is used to connect two or more data points.
Point: It is nothing but a point given at each segment.
To make a line graph we need to use the following steps:
Determine the variables: The first and foremost step is to identify the variables you want to plot on the X-axis and Y-axis.
Choose appropriate scales: Based on your data, determine the appropriate scale.
Plot the points: Plot the individual data points on the graph according to the given data.
Connect the points: After plotting the points, you have to connect those points with a line.
Label the axes: Add labels to the X-axis and Y-axis. You can also include the unit of measurement.
Add Title: After completing the graph you should provide a suitable title.
Reading a Line Graph
To read a line graph you need to follow the below given steps:
Understand the axes: First, you need to understand the X-axis and Y-axis of the graph.
Estimate the scale: Look at the values marked along each axis to determine the scale.
Estimate the values of data points: Look at the data points on the graph to estimate the values on the graph.
Analyze the pattern: Identify the pattern and analyze it.
Conclude: Based on the above step find conclusions.
Example: Draw a line graph for the given data
No. of Days
1
2
3
4
Absentees
5
10
15
10
Answer:
Line Graph between Days and No. of Absentees
The above diagram shows a line graph between No. of days and the number of absentees.
Types of Line Graph
Let us discuss the types of line graphs:
Simple Line Graph
Multiple Line Graph
Compound Line Graph
Simple Line Graph
It is the most common type of line graph in which a single line represents the relationship between two variables over time. The above diagram is an example of a basic line graph.
Multiple Line Graph
It is the type of line graph in which we can represent two or more lines in a single graph and they can either belong to the same categories or different which makes it easy to make comparisons between them. Multiple line graphs also include a double line graph or we can say that a double line graph is also a multiple line graph.
An example of multiple graphs is shown below:
Line Graph between Quantity and Year
In the above graph sale of product A and B is shown in the same graph.
Compound Line Graph
It is a type of line graph in which multiple lines or data are combined into a single graph showing different categories or variables. The main aim of a compound line graph is to represent or display the relationship between different variables on a single graph.
A Compound Line graph example is shown below:
Line Graph between Time and No. Of Vehicles
Advantages of Line Graph
Some of the advantages of using line graph are listed below:
It helps to visualize the data.
It provides a clear overview of the data.
It becomes easy to make predictions using a line graph.
It helps to compare the data more easily.
Note: Line graph is not suitable to show non linear relationship or complex data
