Position-ggproto.RdAll position_ functions (like position_dodge)
return a Position object (like PositionDodge).
The Position object is responsible for adjusting the position of overlapping geoms.
The way that the position_ functions work is slightly different from the
geom_ and stat_ functions, because a position_ function
actually "instantiates" the Position object by creating a descendant,
and returns that.
Each of the Position objects is a ggproto object,
descended from the top-level Position.
PositionDodge_
PositionDodge2_
PositionIdentity_
PositionStack_
PositionFill_An object of class PositionDodge_ (inherits from PositionDodge, Position, ggproto, gg) of length 2.
An object of class PositionDodge2_ (inherits from PositionDodge2, PositionDodge, Position, ggproto, gg) of length 2.
An object of class PositionIdentity_ (inherits from PositionIdentity, Position, ggproto, gg) of length 3.
An object of class PositionStack_ (inherits from PositionStack, Position, ggproto, gg) of length 3.
An object of class PositionFill_ (inherits from PositionStack_, PositionStack, Position, ggproto, gg) of length 2.