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 ?

-- 
http://mutualism.williams.edu