The Plot Canvas

The part of the GUI that displays the plot is called the canvas. The basic presentation of the data is black on white with the location of each data point represented by a symbol. The data subset control, to the right of the canvas, provides a key matching symbols to subsets. When initially displayed, the plot axes are automatically scaled (autoscaled) such that the data points fill the available space. The tick interval and labels are also automatically selected. As seen in the figure, Vupos is capable of labeling time in a friendlier way if it recognizes the data coordinates as time because of the plot file format or if the coordinates are written in the ISO 8601 format. The default format of any dates written as part of a tick label is the ISO 8601 standard four-digit year plus three-digit day-of-year, e.g. 2003-063 for March 4, 2003. An alternate default date format can be set on the command-line or the format can be altered manually using the Attributes menu.

Zooming In and Out

The canvas provides a tool for zooming in on a region of the plot. This is achieved by placing the cursor on the plot, holding down the left mouse button, moving the cursor causing a box to appear on the plot indicating the region which will be expanded, and releasing the mouse button. This process can be repeated to zoom in further if you desire. To zoom out, you can zoom out using the control buttons below and right of the plot: button autoscales the plot and the button zooms back out one step at a time. These same controls are available as a “popup” menu for the canvas. To access this menu, while the cursor is over the canvas, click the right mouse button. The menu should then appear at that location. Note that if you have used the data editing capability of the list, any “killed” points will be excluded from consideration when autoscaling.

Printing

The canvas can be printed using the Ctrl-P shortcut key or through the print option in the File menu. In either case, a printing dialog will appear to facilitate selecting the appropriate printer or, alternately, printing to a file.

$Id: canvas.html 24 2008-04-25 15:12:21Z mark $