Changing the display widget type for a value
You can change the type of widget that displays values with the SmartDashboard. The allowable widgets depend on the type of the value being displayed.
Set edit mode
Make sure that the SmartDashboard is in edit mode. This is done by selecting "Editable" from the "View menu"
Choose the new widget type
Right-click on the widget and select "Change to...". Then pick the type of widget to use for the particular value. In this case we choose LinePlot.
New widget type is shown for the value
The new widget type is displayed. In this case, a Line Plot, will show the values of the Arm angle value over time. You can set the properties of the graph to make it better fit your data by right-clicking and selecting "Properties...". See: Changing the display properties of a value.