How-To: Build a Trellis of Line Charts in Tableau

A trellis chart is a grid where each cell in the grid is the same chart type with the same x- and y-axes but filtered to a different value for some dimension. These can be a useful way to view and compare many values at once.

In this tutorial, we will build a grid where each cell is a line chart of monthly sales over time with each cell showing sales in a different sub-category.

Read on to build your trellis of line charts and find links to further reading to build a other common chart types!

Here's a step-by-step guide using Tableau's built-in Superstore data with screenshots of each step.

Build a Trellis of Line Charts

We use line charts to look at change over time, so you will need a [Date Dimension]. We will use "Order Date" throughout this tutorial.

0. Set up your trellis.

If you haven't done this already, read my blog: How-To: Set Up a Trellis Chart in Tableau.

0. (Optional) Copy your [Breakdown Dimension] onto color.

This can help you ensure your table calcs are configured as desired while building the chart.

2. Create a [Custom Date] from your [Date Dimension].
   1. In your Data Pane, right click your [Date Dimension] and hover over "Create ▶." Select "Custom Date..."
   2. In the window that pops up:
      1. Set "Detail:" to your desired level. This tutorial uses "Month"
      2. Change "Name:" to correspond with your desired level. This tutorial uses "Months"
      3. Make sure the radio button under "Detail:" is set to "Date Value."
   3. Click "OK." You now have a new [Custom Date] dimension available in your Data Pane, with the name you specified.

3. Right click and drag [Custom Date] to the "Columns" shelf and select "ATTR([Custom Date]" in the "Drop Field" window that pops up. Click "OK."

4. Drag your [Measure] onto the "Rows" shelf.

We will use "Sales" as our measure.

5. Drag your [Custom Date] to "Detail" on the "Marks" card.

This will enable you to use [Custom Date] in your table calcs for rows and columns. We can see that our line charts are using data from multiple sub-categories on one chart. We will fix this by adjusting our table calcs.

6. Edit the table calcs.
   1. Click the triangle on the "COLS" pill on the "Columns" shelf.
   2. Select "Edit Table Calculation..."
   3. Choose "Specific Dimensions" under "Compute Using" in the "Table Calculation" pop-up window.
   4. Check the boxes for both your [Breakdown Dimension] and your [Custom Date].
   5. Set "At the level" to your [Breakdown Dimension]. You can now close the "Table Calculation" window.
   6. Repeat for the "ROWS" pill on the "Rows" shelf.

Voila! You have created a trellis of line charts!

Add other chart types to your trellis using my How-Tos:

• How-To: Set Up a Trellis Chart in Tableau.
• How-To: Build a Trellis of Bar Charts in Tableau
• How-To: Build a Trellis of Donut Charts in Tableau

See all these charts in action with embedded How-To blogs here:

How To Build a Trellis Chart Dashboard