The OVERPLOT command lets you graph a data series in a Window that already has a plotted series in it. OVERPLOT puts both sets of data in the same frame of reference. All data points are plotted on the same axes, and thus scroll and scale together.
You can mix graph styles in overplots. For example, you can plot a line chart over a bar chart. The simplest way to change the graph style of individual series in an overplot is to use the crosshair cursor. To do this:
When the overplotted Window is activated, click on the toolbar cursor button.
Use the cursor to "point" to the series whose graph style you want to change. Use the up or down arrow buttons to move the cursor from one overplot to another.
Click on the style icon or press the [F7] key to toggle through the various graphing styles.