Earlier, we briefly opened the View window (see figure 2.7) in order to turn on the marker bar display. Open the View window again, and examine the other controls in it. Three important controls are located along the bottom edge of the window. makes WAVE refresh the signal window, and also closes the View window You should click on in order to see the effects of any changes you make in the View window. The other two buttons in this group are described below.
Along the top of the window, just below the title bar, is a row of on/off controls used to turn on various optional display elements. These controls appear depressed (darker than the background) when they are `on'. The first four of these (subtype, `chan' field, `num' field, and `aux' field) control the display of secondary fields in the annotations. If any of these controls are `on', the corresponding fields are displayed below each annotation mnemonic, in the order shown in the View window.
The Time scale: and Amplitude scale: menu buttons allow you to choose any of a wide range of standard scales for the signal (and Scope) windows. Click right on the to open the menu.
The Draw: menu offers the choice of displaying all signals (the default) or listed signals only (i.e., those named in the Signal list in the Analyze window). By choosing to display listed signals only, you may rearrange the signals within in the signal window. By listing a signal in two or more entries in the signal list, you can arrange to have that signal drawn in two or more locations; this can be useful for making side-by-side comparisons of a signal against several others. You may also find it useful to remove one or more signals from the signal list in order to reduce crowding in the signal window; this technique is nearly essential if the record has more than about 12 signals. (You can also change the spacing between signals uniformly by resizing WAVE 's main window.)
The Show annotations: menu offers three ways to display annotations: centered (the default), attached to signals, and as a signal. If you choose attached to signals, the chan field of each annotation specifies the signal number to which the annotation is attached, and the annotation is displayed slightly above this signal. (Any annotations that have chan fields that are not valid signal numbers for the current record are displayed at the center of the signal window.) If you choose as a signal, the num field of each annotation is taken as the amplitude of a signal at the time of the annotation, and WAVE draws this signal in the center of the signal window by connecting the amplitude/time pairs specified by the annotations with straight line segments.
The Time display: menu provides three alternatives for display of times in the lower corners of the signal window: elapsed (the default), absolute, and in sample intervals. Elapsed time measures the interval in hours, minutes, and seconds from the beginning of the record. Absolute time (i.e., time of day and date) is not defined for all records. If it is available, choosing absolute from this menu will cause WAVE to show absolute times in the signal window, using the color WAVE uses for annotations; otherwise, WAVE switches to elapsed time display. Times may also be displayed in sample intervals (counting from the beginning of the record) for any record; these may be recognized in the signal window by the `s' prefix.
The choice you make from the Grid display: menu determines how WAVE draws the background grid in the signal window. The grid intervals are fixed in time and amplitude units. At the default scales (25 mm/sec, 10 mm/mV) the default grid (0.2 s x 0.5 mV) has 5 mm intervals if the display is properly calibrated. (If this is not the case, see ``How can I get correct display scales?''.) If you change the time or amplitude scales, the grid intervals change size to match, so that you always have a visual cue about the display scale if you leave the grid display on. If you choose a very small time scale (i.e., one that permits WAVE to display a large amount of data in the signal window), the grid may appear solid grey; in this case, you may wish to choose ``1 m x 0.5 mV'' from this menu (so that the vertical grid lines appear at 1-minute intervals), or `0.5 mV'' (thereby suppressing the vertical grid lines), or even ``no grid''. At relatively large scales, where it may be useful to have a finer grid, choose ``0.04 s x 0.1 mV''. To display highly time-compressed data with fine horizontal grid lines, choose ``1 m x 0.1 mV''.
If you make changes in the View window and wish to discard them before clicking on , you may do so by clicking on . This button does not restore the initial values if you have registered earlier changes by using ; to do this, you must restart WAVE .
If, on the other hand, you have made changes in the View window and wish to have WAVE start up with these settings, click on . Note that WAVE saves the current state of the signal window as it appears when you click on ; if you haven't made your changes effective using , they won't be saved.