Legends - R Graphics - page 292

Figure 10-2. Left: legend on top; right: legend inside of graphing area
The legend can also be placed inside the graphing area by specifying a coordinate position, as
in legend.position=c(1,0) ( Figure 10-2 , right). The coordinate space starts at (0, 0) in the
bottom left and goes to (1, 1) in the top right.
Discussion
You can also use legend.justification to set which partof the legend box is set to the pos-
ition at legend.position . By default, the center of the legend (.5, .5) is placed at the coordin-
ate, but it is often useful to specify a different point.
For example, this will place the bottom-right corner of the legend (1,0) in the bottom-right corner
of the graphing area (1,0):
p + theme(legend.position = c( 1 , 0 ), legend.justification = c( 1 , 0 ))