In the chart configuration: is xAxis the same as categoryAxis and is yAxis the same as valueAxis or is there a difference?
It looks like a chart may have many y axes, each of which is an instance of a valueAxis. Each series must specify the y-axis against which it is plotted by setting the series.axis to be equal to the yAxis.name. However, what, then is the purpose of the valueAxis configuration?
Is the situation with xAxis and categoryAxis analogous?