Errorbars to be used with base plotting

errorbars(x, Mean, SE, col, lty = 1, length = 0.07, lwd = 1)

Arguments

x: x value
Mean: mean value or y alternative
SE: standard error
col: color of bars
lty: Line type The line type. Line types can either be specified as an integer (0=blank, 1=solid (default), 2=dashed, 3=dotted, 4=dotdash, 5=longdash, 6=twodash) or as one of the character strings "blank", "solid", "dashed", "dotted", "dotdash", "longdash", or "twodash", where "blank" uses ‘invisible lines’ (i.e., does not draw them).
length: length of the edges of the error bar head (in inches).
lwd: line width

draws lines in the form of error bars

see arrows() function

x.val=c(1,2,3)
mean.val=c(2,5,7)
se.val=c(0.1,0.5,1)
plot(mean.val~x.val,ylim=c(0,10))
errorbars(x.val,mean.val,se.val,"red")