You define your own function for the confidence intervals. The function needs to return the two values representing the upper and lower CI values. So:
qt.fun <- function(x) qt(p=.975,df=length(x)-1)*sd(x)/sqrt(length(x)) my.ci <- function(x) c(mean(x)-qt.fun(x), mean(x)+qt.fun(x)) lineplot.CI(x.factor = dose, response = len, data = ToothGrowth, ci.fun=my.ci) Manuel On Fri, 2009-05-22 at 18:38 +0200, Jarle Bjørgeengen wrote: > Hi, > > I would like to have lineplot.CI and barplot.CI to actually plot > confidence intervals , instead of standard error. > > I understand I have to use the ci.fun option, but I'm not quite sure > how. > > Like this : > > > qt(0.975,df=n-1)*s/sqrt(n) > > but how can I apply it to visualize the length of the student's T > confidence intervals rather than the stdandard error of the plotted > means ? > -- http://mutualism.williams.edu ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.