This example demonstrates the tabsetPanel and tabPanel widgets.

Notice that outputs that are not visible are not re-evaluated until they become visible. Try this:

1. Scroll to the bottom of server.R
2. Change the number of observations, and observe that only output$plot is evaluated.
3. Click the Summary tab, and observe that output$summary is evaluated.
4. Change the number of observations again, and observe that now only output$summary is evaluated.