First sample data is generated to render an instance of a first graph element type with a first axis. Second sample data is generated to render an instance of a second graph element type with a second axis parallel to the first axis. Data points used for the first axis are different from data points used for the second axis. A first axis selector is presented in association with the first axis. An indicator is received that indicates selection of the presented first axis selector. After receipt of the indicator, a second indicator is received that indicates selection of a shared role between the first axis and the second axis. After receipt of the second indicator, the instance of the second graph element type is rendered with the first axis. Third data points used for the second axis automatically have the same value as first data points used for the first axis.