Add error bars to show standard deviation on a plot in R

Question

For each X-value I calculated the average Y-value and the standard deviation (sd) of each Y-value

x  = 1:5
y  = c(1.1,         


        

Answer 1

In addition to @csgillespie's answer, segments is also vectorised to help with this sort of thing:

plot (x, y, ylim=c(0,6))
segments(x,y-sd,x,y+sd)
epsilon <- 0.02
segments(x-epsilon,y-sd,x+epsilon,y-sd)
segments(x-epsilon,y+sd,x+epsilon,y+sd)