When you click on the "i" button in the graph window, or select "Graph Info..." from the Graph menu, you are shown the following floating window. From this window, you can modify the attributes of the current graph (or currently-selected gate). The first time you are shown this window, the bottom two "sections" are hidden; click on the triangles to reveal them.

Use the gating tools (top) when you want to create a new gate of a particular kind. The quadrant tool is a special case: it creates four gates (click here for more information). The next section lets you select which parameters to view; the third section defines the graph type and options. The fourth section is disabled unless the current graph is a histogram or CDF, in which case you could select to change the vertical (Y-axis) scaling for the plot. Finally, the bottom section is enabled whenever you have a single gate selected in the graph window. Here you can choose to gate for events inside or outside the gate, and choose to draw the gate in a different color than the default. Tinting the area inside the gate only alters the drawing of the gate; it does not change the colors of any events (dots) on any of the graphs.

"Magnetic" gates automatically move to accomodate the maximum event density. For more information, click here.

You do not have to close this window; you can leave it in one corner of your screen. It automatically updates itself to reflect any new graph window that you open.