Add components to a plot — add_gg

Arguments e1 An object of class ggplot() or a theme(). e2 A plot component, as described below. What can you add? You can add any of the following types of objects: An aes() object replaces the default aesthetics. A layer created by a geom_ or stat_ function adds a new layer. A scale overrides the existing scale. A theme() modifies the current theme. A coord overrides the current coordinate system