1. A method in a data processing system having a display showing a chart, the method comprising the steps of: receiving a first series of numerical values having first tags indicating characteristics of the numerical values; displaying the first series of numerical values on the chart, the first series of numerical values corresponding to a first axis on the chart; receiving a second series of numerical values to be added to the chart, the second series of numerical values having second tags indicating characteristics of the second series of numerical values; in response to receiving the second series, automatically generating a second axis on the chart; displaying the second series of numerical values on the chart corresponding to the second axis while the first series is displayed on the chart; determining an axis label on the chart; automatically determining a new axis label based on at least one of the first tags and the second tags; and displaying the new axis label on the chart.