Axes - R Graphics - page 222

Figure 8-6. Box plot with reversed y-axis
Discussion
Like scale_y_continuous() , scale_y_reverse() does not work with ylim . (The same is
true for the x-axis properties.) If you want to reverse an axis andset its range, you must do it
within the scale_y_reverse() statement, by setting the limits in reversed order ( Figure 8-7 ) :
ggplot(PlantGrowth, aes(x = group, y = weight)) + geom_boxplot() +
scale_y_reverse(limits = c( 8 , 0 ))
Figure 8-7. Box plot with reversed y-axis with manually set limits