ptukey(q, nmeans, df, nranges = 1) qtukey(p, nmeans, df, nranges = 1)
q
| vector of quantiles. |
p
| vector of probabilities. |
nmeans
| sample size for range (same for each group). |
df
| degrees of freedom for s (see below). |
nranges
| number of groups whose maximum range is considered. |
pchisq.
If ng =nranges is greater than one, R is
the maximum of ng groups of nmeans
observations each.
ptukey gives the distribution function and qtukey its
inverse, the quantile function.ptukey.
The computations are relatively expensive, especially for
qtukey which uses a simple secant method for finding the
inverse of ptukey.
qtukey(..) will be accurate to the 4th decimal place.pnorm and qnorm for the corresponding
functions for the normal distribution.system.time(curve(ptukey(x, nm=6, df=5), from=-1, to=8, n=101)) (ptt <- ptukey(0:10, 2, df= 5)) (qtt <- qtukey(.95, 2, df= 2:11)) ## The precision may be not much more than about 8 digits: summary(abs(.95 - ptukey(qtt,2, df = 2:11)))