Showing the Difference Between Two Points in a Tableau Line Chart

When working with a line chart, you may sometimes want to know the difference between two points. In such cases, you can use Tableau’s parameter actions to capture date values and apply them in conditional logic to display the rate of change directly on your dashboard.

In this example, the following features are implemented:

• The rate of change is displayed based on the more recent of the two selected points.
• The area between the two selected points is shaded.
• If one of the two selected points is clicked again, that selection is canceled.
• If a point outside the two selections is clicked, the previous selections are reset, leaving only the newly selected point.