If the Input Window is not currently displayed, select this menu item to open it.
If the Graph Window is not currently displayed, select this menu item to open it.
Select this menu item, then move the cursor horizontally on the graph screen to drag the red diamond marker along the displayed trace.
Select this item, then click and drag the cursor within the graph screen to outline a rectangle. This is the zoom area.
When you release the mouse button, the region of the graph which you outlined with the rectangle expands to fill the graph window.
Select this menu item to cancel the effect of the zoom, and restore the automatically scaled graph view.