Various kinds of plots

# Balloon Plot

ggplot(data = RhythmData, aes(x=Time,y=Participant,size=Intensity,fill=Intensity)) + 
  geom_point(shape=21, colour="skyblue3") + scale_size(guide="none") +
  scale_fill_gradientn(colours = c("lightblue", "steelblue", "midnightblue")) +
  theme_grey(base_size=8, base_family="Verdana") + 
  theme(panel.grid.minor=element_blank(), panel.grid.major.x=element_line(colour="white",size=0.1), panel.grid.major.y=element_line(colour="white",size=0.1))