The appearance of the plot area depends on the screenwidth (the width of the screen in pixels) and the number of cases.  If the file contains <= screenwidth cases, data are plotted 1 pixel per case (if the number of cases is < 50% of screenwidth, the plot is expanded, with more than 1 pixel per case).  If the total number of cases is more than screenwidth, the X-axis will be scaled to fit within the screen dimensions.  'Screens' (consisting of screenwidth cases) are indicated by vertical lines, with a crossbar at the top of the active screen.  The example shows a file containing many screenwidths of data. 

You can alter the font size of the 'ToolTips' that appear if you hover the cursor over any of the toolbar buttons (this also applies to the channel number selection buttons in many ANALYSIS windows).  However, this requires using the Terminal function (in the Utilities folder, which is in the Applications folder).  In Terminal, type this exactly to set ToolTip font size (here, to 14 points; you can use other sizes): defaults write -g NSToolTipsFontSize -int 14 To set the delay before the ToolTip appears (here, to 20 milliseconds): defaults write -g NSInitialToolTipDelay -int 20 Hit 'return' after typing these commands.   NOTE:   these commands affect not just the Warthog software, but also any other application that uses ToolTips.

If there are more than screenwidth cases, the bottom of the plot area will show a screen selection slider, with tickmarks to indicate the number of 'screenfulls' of data in the file (for very large files, not all tickmarks are shown, for clarity). The currently 'active' segment of the file -- the active screen - is indicated by the slider position.  Drag the slider with the mouse, or use the left and right arrow keys to change the active screen.  To view the active screen only (necessary for some manipulation and analysis operations), hit the shift or return keys.  Do this again to go back to viewing the entire file (this example shows 'entire file' mode).  Any markers are shown as vertical dashed lines (this file contains numerous markers, but they are not shown; see the VIEW menu).  While in the plot area, the cursor is a cross-hair; out of the area it is an arrow.  The data bar has a readout of case number, elapsed time, and the value of the currently active channel at the cursor position. The time of day is shown (24-hour scale) along the bottom of the plot area, with optional hour indicators (vertical dotted lines).

To perform analyses and some transformations, you need to select a data block. This can be done by the normal 'click-hold-and-drag' method (the cursor must be within the plot area).  A second method uses individual clicks: move the cursor to the desired start point and click once; repeat for the end point (which may be on either side of the start point).  Alternately, blocks of defined width can be selected with single clicks (see the BLOCK WIDTH option in the ANALYZE menu).  If there is sufficient space, you can 'shift' blocks to the left or right with the BLOCK SHIFT commands (also in the ANALYZE menu).
      You can select blocks in 'entire file' or in 'active screen only' mode, and blocks can include multiple screens.  If a single screen is shown, mark the start with a single click, then shift screens until the end can be marked.  A selected block is indicated as a color-inverted rectangle in the plot area, and is scaled to fit within the block window (discrete data points on the block window only appear if the number of included points is small).