Creating a tree map

To follow this recipe, open B05527_01 – STARTER.twbx. Use the worksheet called Tree Map, and connect to the Data (Modified Gapminder Population) data source.

The following are the steps to create the population tree map:

A tree map allows us to present a part-to-whole relationship, just like a pie chart, but by subdividing a rectangle into smaller areas rather than subdividing a circle into different angled slices.

In Tableau, when you place a measure onto Size and a dimension onto either Color, Label, or Detail—or any combination thereof—the rectangle is broken down into smaller rectangles.

In this scenario, Tableau actually automatically assigns the Square mark. Although under Marks you will see Automatic, the icon refers to a Square. If you leave this as Automatic, or change the Mark explicitly to Square, you will get the same tree map.

Pie charts get a bad reputation because angles and slices are not easy to compare. Bubble charts are also hard to compare, because it is also hard to compare diameters and circumferences. Guess what, tree maps also fall into this same category. It is also not easy nor natural for us humans to discern and compare one area to another. Can we tell how much bigger or smaller one rectangle is compared to another? However, as with the other charts, with the right intent, audience, and story, this could be an effective chart—either by itself, or as a complementary chart to another.