DescTools (version 0.99.44)

PlotProbDist: Plot Probability Distribution

Description

Produce a plot from a probability distribution with shaded areas. This is often needed in theory texts for classes in statistics.

Usage

PlotProbDist(breaks, FUN, 
             blab = NULL, main = "", xlim = NULL, col = NULL, density = 7, 
             alab = LETTERS[1:(length(breaks) - 1)], alab_x = NULL, alab_y = NULL)

Arguments

breaks

a numeric vector containing the breaks of different areas. The start and end must not be infinity.

FUN

the (typically) distribution function

blab

text for labelling the breaks

main

main title for the plot

xlim

the x-limits for the plot

col

the color for the shaded areas

density

the density for the shaded areas

alab

the labels for areas

alab_x

the x-coord for the area labels

alab_y

the y-coord for the area labels, if left to default they will be placed in the middle of the plot

Value

nothing returned

Details

The function sets up a two-step plot procedure based on curve() and Shade() with additional labelling for convenience.

See Also

Shade, curve, polygon

Examples

# NOT RUN {
# plot t-distribution
PlotProbDist(breaks=c(-6, -2.3, 1.5, 6), 
             function(x) dt(x, df=8), 
             blab=c("A","B"), xlim=c(-4,4), alab=NA,
             main="t-Distribution (df=8)",
             col=c(hred, hblue, horange), density=c(20, 7))

# Normal
PlotProbDist(breaks=c(-10, -1, 12), 
             function(x) dnorm(x, mean=2, sd=2), 
             blab="A", xlim=c(-7,10),
             main="Normal-Distribution N(2,2)",
             col=c(hred, hblue), density=c(20, 7))

# same for Chi-square
PlotProbDist(breaks=c(0, 15, 35), 
             function(x) dchisq(x, df=8), 
             blab="B", xlim=c(0, 30),
             main=expression(paste(chi^2-Distribution, " (df=8)")),
             col=c(hblue, hred), density=c(0, 20))
# }