This parameter magnifies the vertical axis. Click on the combo box to select the setting you want. Start with the lower settings and work up to higher settings as needed. If Magnify is set too high for a particular set of data, none or only a few points may be plotted. Also, increasing the Magnify level may not change the vertical scale, because the data can not always be scaled to the next Magnify level. The Auto setting provides a near best view of the data.
With Magnify set to anything other than off, it's normal for some traces to end (drop below the X-axis) before they reach the full range of the graph.