To choose which cursor to use, see the menu commands under Graphs / Options / Cursor within a Graph window.
When using either the Track Ball or Crosshair cursor types the cursor can optionally "snap" to the plotted values in the graph. When snap is on, the cursor will be positioned over the closest plotted data point to the mouse location. If snap is turned off, the cursor is free floating and will indicate the mouse position. The value where the cursor is located will be displayed in the status bar, and this location will be highlighted with either a small Track Ball or a large Crosshair. If the option to show cursor labels is checked the location will be displayed in labels at the edges of the graph window. When the cursor is off, no highlighting occurs, and the value directly beneath the cursor is displayed in the status bar.
Cursor labels are only displayed if the entire graph window is within the application window.
Tip: Use the keyboard shortcut 'F3' to scroll between the different cursor types.