The "ptukey" and "qtukey" functions may be what you want (or at least in the right direction).
You could also easily estimate this by simulation. Hope this helps, -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare [EMAIL PROTECTED] (801) 408-8111 > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Spencer Graves > Sent: Friday, March 21, 2008 11:13 AM > To: r-help@r-project.org > Subject: [R] function for the average or expected range?; CORECTION > > Hi, All: > > ** My previous email on this subject seemed to contain an > error; check the correction: > > Is there a function in R to compute the expected range > of a sample of size n from some distribution? I ask, because > I was recently asked about the control chart constant 'd2', > which is the expected range for a sample of size n from a > standard normal. > > There is a fairly simple formula for the expected value > of the range, given, e.g., in Kendall and Stuart (1969) The > Advanced Theory of Statistics, vol. 1, Distribution Theory, > 3rd ed. (Hafner, expression (14.82), sec. 14.25: The exact > distribution of the range, p. 339). > Unfortunately, either I don't understand this formula, or it's wrong. > Using expression (14.1) in the same reference, I get the following: > > E(R) = n*integral{-Inf to Inf of [(F(x))**(n-1) - > (1-F(x))**(n-1)]dF(x). > > Thanks, > Spencer Graves > > ______________________________________________ > 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. > ______________________________________________ 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.