This is the second part of a four-part series on Tableau Playbook - Dual Axis Line Chart. In the first part, we delved into basic concepts of the dual axis line chart when it is combined with a line. Check it out in case you missed it.
In this guide, we will focus on another dual axis line chart: Line Chart Dual Axis with Dot. By analyzing a real-life dataset: Rossmann Store Sales, we will focus on how to build it step by step. Meanwhile, we will draw some conclusions from Tableau visualization.
We’ll sample a representative store for each StoreType and analyze their weekly sales trends. In this example, we’ll use the dual axis technique to emphasize individual store samples.
Create a set for store samples. The specific sampling results are: a - 238, b - 512, c - 897, d - 94.
First, create a discrete line chart:
Display "StoreSample" as color in this line chart.
Drag "StoreSample" from Sets into Marks - Color.
In Tableau, a Set shows IN/OUT by default. It reflects a Boolean relationship. The IN is everything that is inside of my set (i.e. these four store samples) and the OUT is everything that does not qualify for my set.
In this chart, we intend to show the items in the set, so we right-click StoreSample and choose Show Members in Set. We can see a filter is added automatically.
Here we introduce the second way to build the dual axis.
Add shapes to dots to emphasize on individuals of store samples.
Here we choose "StoreType" to represent the shape. Actually "StoreSample" and "StoreType" are the same in this example because "StoreSample" is sampled according to "StoreType"'.
Drag "StoreType" into Marks - Shape in the second Marks card.
Click the inverted triangle in shape Legend and choose Edit shape...
Select Filled in the Shape Palette.
Optimize the shapes:
Put on the finishing touches:
We use four typical stores to represent the corresponding StoreType. Aided by the dual axis with dot, we can distinguish individuals more clearly with shapes and colors.
With a quick scan, we can draw some conclusions. For example, only Store 512 opens on Sunday. Store 94 and Store 238 have similar sales and trends. They both have the highest sales on Monday and continuously go down the rest of the week until Saturday.
In this part, we have learned how to create a line chart dual axis with dot. First, we created a set for store samples. Then, we built a raw discrete line chart. Next, we used the dual axis with dot and customized the shape. In the end, we dug out useful information from this chart.
In the third part, we will practice the line chart dual axis with area.
You can download this example workbook Line Chart and Variations from Tableau Public.
In conclusion, I have drawn a mind map to help you organize and review the knowledge in this guide.
I hope you enjoyed it. If you have any questions, you're welcome to contact me at [email protected]