sciplot question
Great, thanks Manuel. Just for curiosity, any particular reason you chose standard error , and not confidence interval as the default (the naming of the plotting functions associates closer to the confidence interval .... ) error indication . - Jarle Bj?rgeengen
On May 24, 2009, at 3:02 , Manuel Morales wrote:
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 Bj?rgeengen 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 ?