Each chart, except for a pie chart, has horizontal and vertical axes. There are two axis types: category and numeric. A category axis typically defines strings that represent groupings of items in the chart; for example, types of expenses (such as rent, utilities, and insurance) or names of employees. A numeric axis typically defines continuous data such as the amount of an expense or the productivity gains of the employee. These data define the height of a column, for example. Numeric axes include the LinearAxis, LogAxis, and DateTimeAxis.

You work with the axes objects to define their appearance, but also to define what data is displayed in the chart.

The following sections describe the CategoryAxis and NumericAxis classes.