pos
Parameter to set the position of the legend. Can be given in form of a string
(bottom|top)(right|left) for base graphics and bottom|top|left|right
for ggplot2. It can be a two-elements vector, which specifies the relative position on
the x and y axis respectively, or alternatively it can be in form of a logical variable,
with FALSE indicating to use the default position and TRUE to place it on
the bottom of the plot. Default value is c(0,1), that is in the topleft corner
inside the plot area.