Xcelsius 2008 introduced a global dual axis chart capability that works quite well. I put together a simple example below, illustrating the technology. A dual axis chart is relevant when you are trying to draw indirect correlations between two different measures. I have never seen an effective use of dual axis charts where same measure is displayed on both y axis. The Y Axis toggle in Xcelsius is locate in the general tab for most vertical oriented charts.
Here are a few best practices that make these charts easier to visually digest in Xcelsius:
- Always include vertical axis labels for the left and right Y axis.
- Always show the legend on the top or bottom of the chart to ensure there is enough room for both vertical axis labels and titles.
- Use colors that make it easy to differentiate between each series.