Why does the Y-axis on some graphs not start at zero?

Sometimes Netreo needs to display data in a graph where the full range of data values displayed never approach the zero or max. values of the graph.

To avoid compressing the (vertical) display of such data (which could blunt the appearance of important variations), Netreo may dynamically zoom the graph along the Y-axis.

When displayed this way, the lowest Y-axis value the graph will show is slightly lower than the lowest displayed data value and the highest Y-axis value is slightly higher than the highest displayed data value. This allows the display of data to utilize the full size of the graph and show variations in the data values as clearly as possible. (This function is controlled by the software and does not change when a user manually zooms the X-axis of a graph.)

Y-axis zooming is most frequently seen

Example of a graph with the Y-axis zoomed (below). Notice that the Y-axis starts at 20 (rather than 0) and peaks at 80 (rather than 100).

Do not assume that data points near the bottom of a graph are low values or that points near the top are high values. It is important to make sure that you pay attention to the actual graph values when viewing data in Netreo and be sure of what the graph is actually showing.