#在sciplot程序包里可以自动加误差线

install.packages("sciplot")     #安装sciplot包

library(sciplot)                  #调用sciplot包

bargraph.CI(dose, len, data = ToothGrowth)

lineplot.CI(dose, len, data = ToothGrowth)

# 巧用箭头作为误差项方案，其实这个更实用，因为我们可以自己定误差线，或是置信区间的线

x  = 1:5

y  = c(1.1, 1.5, 2.9, 3.8, 5.2)

SD = c(0.1, 0.3, 0.2, 0.2, 0.4)

plot (x, y)

# add error bars (without adjusting yrange)

arrows(x, y-SD, x, y+SD, length=0.05, angle=90, code=3)

# new plot (adjusts Yrange automatically)

plot (x, y,ylim=c(1,6))

arrows(x, y-SD, x, y+SD, length=0.05, angle=90, code=3)