Index

Zooming and autoscaling the Y-axis of a plot

To interactively modify the y-axis range of a graph, start by switching to the y-zoom cursor-input mode, either by pressing the "y" key within the plot window, or by pulling down the Cursor menu of the plot window and selecting Zoom Y. The cursor will change to a single horizontal line. If you want to increase the y-axis range to reveal all of the available data that lies between the current x-axis range, press the right mouse button. If you want to temporarily zoom in on the y-axis of a graph, start by moving the horizontal cursor line to one end of the desired y-axis range within the graph, then click the right mouse button. The cursor will split into two horizontal lines, one of which stays where you just clicked, and the second of which should be moved to the other end of the range. Upon clicking the left mouse button again, the plot will be zoomed to display the data between the two cursor lines. If you didn't zoom in as far as you wanted, you can repeat the above operations to zoom in further. The viewer keeps a stack of all these nested zooms, so that unzooming takes you back to the previous zoom limits.

Unzooming the y-axis

To unzoom the y-axis after zooming in one or more times, if you aren't still in y-zoom cursor input mode, select it as described above, then press the right mouse button. Each time that you press this button, the graph will unzoom back to the previous zoom limits, until all the nested zooms have been undone. If you then press this button again, the y-axis range will be increased just enough to reveal all of the data that lies within the current x-axis limits.

Adopting zoom limits

If after zooming in, you want to forget about all nested zoom limits and adopt the current zoom limits as the normal graph limits, press the middle mouse button. This will update the limits shown in the plot configuration dialog, and those that are recorded when you save the plot configuration.
Martin Shepherd (6-Nov-1999)