While working for a retail furniture supplier company, we were analysing the quarterly sales trend over the current and previous years. To visualize this data, I created a Line chart that shows Sales over the year, divided by quarters of the year. Using the line chart, we were able to identify sales patterns like where it was drops and spikes in the sales figures.
In this blog, I will explain about the Line chart in Tableau, and how you can use it to visualize and analyse your data.
What is a Line Chart in Tableau?
In Tableau, a Line chart is used to show how data changes over a period of time by comparing date values. It displays the data points for the values connected through a straight line. Each point on the line represents a value at a specific time, and when connected, the line indicates whether the values are increasing, decreasing, or remaining constant.
In Tableau, there are two main types of line charts: continuous line charts and discrete line charts. Both of these line chart types can be accessed from the Show Me menu when creating a line chart.
Continuous Line Chart:
In the Tableau continuous line chart, we have the line connecting the dots of data points on the continuous axis. The values on the axis are in sequence without breaks, such as days, months, or years.
For example, to track the quarterly sales of two years, a continuous line chart in Tableau will show the rise or fall of sales quarter by quarter by connecting the data points.
Discrete Line Chart:
A discrete line chart in Tableau uses separate values on the axis, like specific months, categories, or regions, rather than a continuous line across a range of values. These values are considered as labels instead of a continuous flow.
To create the discrete chart, we use a date or dimension field on the Columns or Rows shelf, resulting in individual lines for each category.
Check out: Tableau Dual Axis Chart
Differentiate the Continuous and Discrete fields:
In the Dimension side bar, we see a number of fields; the ones we see in green color are the continuous fields, and the ones with blue color are the discrete fields.
Create a Line Chart in Tableau
In the examples below, we will create a line chart for both the Continuous line chart and the Discrete line chart.
Create a Discrete Line Chart in Tableau
In this example, we will create a line chart using the date dimension. In the line charts, the date dimension is the only exception that can be both continuous and discrete.
The line chart below displays the product sales for each quarter over the years.
- In the Rows shelf, add the Sales dimension. After this, add the Order Date to the Columns field.
After adding the order date to the columns, by default, it will be in the year format.
Now, the chart will automatically display in the line format after adding the Date and Sum fields.
- To make the chart discrete, we will add another Order Date again to the Columns and change the format to Quarter.
Now, the line chart will be divided into sales for each quarter of a specific year.
As we can see after breaking down the data into quarters, separate sections are created for each year, displaying their quarterly sales in a single continuous part. Here, the first line chart has no connection with the other one hence it is a discrete chart.
Check out: Bullet Chart in Tableau
- To display the sales values in each quarter for specific years, add the Sales to the Label card in the Marks section.
This is how you can create a discrete line chart in Tableau, where each section displays a line chart that has no relationship with the other sections’ line charts.
There are a few instances when you can confuse a discrete line chart with a continuous one. Although we can differentiate between the green and blue colors of fields, some discrete charts appear as continuous.
For example, if we remove the Year(Order date) from the above chart, the Rows will have a discrete part of all the quarters. Here, Quarter 1 (Q1) will display the sales of Q1 for all years.
To determine the years, we again need to add the Year (Order date). This will display the discrete line charts. To see the connection between all the years for each quarter, we need to create a continuous line chart.
Check out: Tableau Gauge Chart
Create a Continuous Line Chart in Tableau
To create the Continuous Line Chart, we take the same example as the previous one, where we will display the yearly Sales trends for all quarters for each year.
Unlike the discrete chart, the continuous chart will display the relationship between all the years.
- Add the Order Date to the Rows and Sales field to the Columns.
- Now, you will see the Order Date in blue color, which means it is discrete. To make the date field continuous, click on it and select Year.
Here, you will see duplicate date values, so the top ones are discrete and the bottom ones are continuous.
- As we select the Year from the continuous date field, the Year(Order Date) will be in green color, which indicates that it is a continuous field now.
To add other measures, like Quarter, click on the ‘+’ icon on the date field.
- Now, you will see that the added fields Quarter and Years will appear in the same field. It won’t create a separate field in the Columns and won’t display a different chart.
As we hover over the data point in the line chart, it will display the quarter and year corresponding to that data point.
- At last, to display the sales figures, add the Sales field to the Label card in the Marks section.
This way, by following the steps, we can convert a discrete date field to a continuous one and create a continuous Line Chart in Tableau.
I hope the examples that we have discussed above help you understand how to use line charts in Tableau, how to differentiate between continuous and discrete line charts in Tableau, and select the correct one for the data visualization.
You may also like to read:
- Tableau Funnel Chart
- Gantt Chart in Tableau
- Build a Bar in Bar Chart in Tableau
- Pareto Chart in Tableau
- Lollipop Chart in Tableau
I am Bijay Kumar, the founder of SalesforceFAQs.com. Having over 10 years of experience working in salesforce technologies for clients across the world (Canada, Australia, United States, United Kingdom, New Zealand, etc.). I am a certified salesforce administrator and expert with experience in developing salesforce applications and projects. My goal is to make it easy for people to learn and use salesforce technologies by providing simple and easy-to-understand solutions. Check out the complete profile on About us.
