PillarSoft

http://www.pillarsoft.net/help/os2/bgmetric/charts.shtml

BgMetrics - Charts

The charts page will help you visualize some of the data you have been tracking. On the line charts, when there is no entry in a field of the line representing that column of data, the line will remain flat with no increase or decrease. This will prevent inverted spikes in the graph for those times with no entry.

There are several ways to view the charts. These methods are explained further in the Graph data and Chart Data Dialog sections as well as in the menu explanations that follow.