Bump charts are an effective way to explore how rankings change over time. However, formatting bump charts in Tableau to be visually effective can be tricky. This blog will first demonstrate how to construct a simple bump chart in Tableau, then give a few tips to improve its presentation ensuring key insights are successfully communicated to your audience.
Basic Setup:
First, you’ll want to gather your data and connect it to Tableau. I’ll be using data about popular stocks and cryptocurrency. Download the data here if you’d like to follow along with this example.
- Right-click and drag a discrete date variable to the Columns shelf,
- Drag the variable you want to rank by to the Rows shelf.
- Drag the variable containing the categories you want to rank against each other to Color in the Marks card.
- Select Entire View from the top ribbon to ensure your chart is appropriately sized.
Optional: I’ll add a filter to my categories so that my chart will only rank cryptocurrencies.
Ranking Your Categories:
- Hover over the variable on the Rows shelf, click the drop-down arrow, and select Add Table Calculation…
- Select Rank from the Calculation Type drop-down menu. From the options that appear, ensure the rank order is Descending.
- Click Specific Dimensions from the Compute Using section and select the categories option (the groups being ranked against each other).
- From here, right-click the y-axis (the rank axis), click Edit Axis, and then select Reverse Axis in the pop-up window. This will place the highest-ranking category at the top.
General Formatting Tips:
Bump charts should be easy to view and interpret. The chart we have made is simple but can be improved significantly in terms of readability. Here is a video demonstration of various tips to improve the formatting followed by a written description of each.
1) Give Your Chart a Descriptive Title
Simple enough right? Indicating that you have made a chart that ranks categories makes interpreting it that much easier. In our case, it might be something like “Popular Cryptocurrencies Ranked by Close Value Each Year”.
2) Remove the Y-Axis Labels
Remove the y-axis labels by right-clicking on this axis and deselecting Show Header. Why did we do this? well, in the next step we will want to add some labels to each line’s start and end points with their ranking, so this axis won’t be providing any additional information.
3) Add Labels to the Start and End of Each Line
Depending on what your bump chart requires, this could be done in a few ways. To get descriptive start and end point labels:
- Right-click and drag the ranking variable from the Rows shelf to Label in the Marks card.
- Drag my categories variable to Label as well.
- Click Label in the Marks card, tick show mark labels, and select Line Ends under the Marks to Label
- In Label, click the ellipses (“…”) next to Text, and edit your labels appropriately.
- Then go to Font in the Label card, click the drop-down, and select Match Mark Color.
4) Format Gridlines
This is mostly up to personal preference, but I like to remove horizontal gridlines for bump charts and add faint vertical gridlines. This just helps to line up the years to each category and make quick, yet accurate, comparisons.
5) Change the Date Variable to be Continuous
Hover over the data variable in the Columns shelf, click the drop-down arrow, and select Continuous near the bottom of the drop-down menu. This will move the x-axis label to the bottom, align your vertical gridlines to the years on the x-axis, and give your line labels some breathing room on the sides of your chart (in some cases, this may also fix misaligned labels).
There you have it. A well-formatted bump chart in Tableau. Thank you for reading! If you’re interested in any other Tableau or Power BI tips and tricks, feel free to read more on my page. Happy visualising!