这是一套为初学者学习R语言画图、写论文所准备的教程，开发不易，且看且珍惜
# Library
install.packages("hrbrthemes")
library(viridis)
library(hrbrthemes)
# Plot
ggplot(data, aes(x=time, y=value, fill=group)) +
geom_area(alpha=0.6 , size=.5, colour="white") +
scale_fill_viridis(discrete = T) +
theme_ipsum() +
ggtitle("The race between ...")