mosaic (version 0.10.0)

qdist: Illustrated quantile calculations from distributions

Description

Illustrated quantile calculations from distributions

Usage

qdist(dist = "norm", p, plot = TRUE, verbose = FALSE, invisible = FALSE,
  resolution = 5000L, digits = 4L, xlim, ylim, vlwd = NULL,
  vcol = trellis.par.get("add.line")$col, rot = 45, ...)
xqgamma(...)
xqt(...)
xqchisq(...)
xqf(...)
xqbinom(...)
xqpois(...)
xqgeom(...)
xqnbinom(...)

Arguments

dist

a character discription of a distribution, for example "norm", "t", or "chisq"

p

a vector of probabilities

plot

a logical indicating whether a plot should be created

verbose

a logical

invisible

a logical

resolution

number of points used for detecting discreteness and generating plots. The defaut value of 5000 should work well except for discrete distributions that have many distinct values, especially if these values are not evenly spaced.

digits

the number of digits desired

xlim

x limits

ylim

y limits

vlwd

width of vertical lines

vcol

color of vertical lines

rot

angle for rotating text indicating probability

...

additional arguments, including parameters of the distribution and additional options for the plot

Value

• a vector of quantiles; a plot is printed as a side effect

Details

The most general function is qdist which can work with any distribution for which a q-function exists. As a convenience, wrappers are provided for several common distributions.

Examples

qdist("norm", seq(.2, .8, by=.10))
xqnorm(seq(.2, .8, by=.10), mean=100, sd=10)
qdist("unif", .5)
xqgamma(.5, shape=3, scale=4)
xqchisq(c(.25,.5,.75), df=3)
xpbinom( c(480, 500, 510), size=1000, prob=0.48)
xqpois( c(0.25, 0.5, 0.75), lambda=6, lwd=3, vlwd=2)