Annotating visualizations with reference lines, fitted curves, and error bars
Adding horizontal and vertical lines to a visualization to indicate limits or boundaries can significantly enhance the information you wish to convey. Take, for example, the batting performance visualization we created in Chapter 5, Source Data is Never Enough. We colored by quadrant, and we can further enhance that visualization by adding appropriate reference lines.
Open the scatter plot's visualization properties and select Lines & Curves. You can use any pre-existing vertical and horizontal lines or select from the drop-down list provided by the Add button.
Check the boxes next to Vertical Line: 0.00 and Horizontal Line: 0.00, and edit each to change the Line position to "Median." You can also change the color and thickness of the lines if you wish, using the Appearance settings.
The result of this reference line configuration is the appearance of horizontal and vertical lines corresponding to the color boundaries...