Graph Zooming

The zoom feature allows the user to expand a section of the graph to allow more precise measurements of points on the graph. The original graph contains about ten thousand points. Zooming does not recalculate new points, it just shows the original points connected by lines.

• Move the mouse cursor over the graph at a corner of the desired region to select. Hold down the right-mouse button and move the mouse to create a rectangle. Let go of the mouse when the rectangle encloses the desired zoom region.
• If the wrong region is selected by accident, then click the right-mouse button once and the selection rectangle will be cleared.
• When the desired region is selection, either click the mouse middle button, or strike the 'Z' key on the keyboard, to zoom in on the selected region of the graph.
• The user can zoom in on a zoomed graph region again. This can be done more than once. Eventually it will not be possible to zoom anymore. If zooming many times, on my very fast system, it can take several seconds for zooming to complete. This will rarely happen, and might be an issue on slow systems.
• To display the original unzoomed graph again, either strike the 'R' key on the keyboard, or select the "Graph" menu item and click the "Refresh" submenu item. If the Filter Designer dialog window is open, you can also click the "Apply" button on the dialog window, however, unlike the previous two methods to unzoom the graph, clicking the "Apply" button will recalculate the filter.

A selected region before zooming

After zooming