shade.norm: Shading functions for interpretation of pdf probabilities.

In asbio: A Collection of Statistical Tools for Biologists

Shading functions for interpretation of pdf probabilities.

Description

Creates plots with lower, upper, two-tailed, and middle of the distribution shading for popular pdfs.

Usage

shade.norm(x = NULL, from = NULL, to = NULL, sigma = 1, mu = 0,
tail = "lower", show.p = TRUE, show.d = FALSE, show.dist = TRUE, digits = 5,
legend.cex = .9, shade.col="gray",...)

shade.t(x = NULL, from = NULL, to = NULL, nu = 3, tail = "lower", 
show.p = TRUE, show.d = FALSE, show.dist = TRUE, digits = 5,legend.cex = .9, 
shade.col="gray",...)

shade.F(x = NULL, from = NULL, to = NULL, nu1 = 1, nu2 = 5, 
tail = "lower", show.p = TRUE, show.d = FALSE, show.dist = TRUE, 
prob.to.each.tail = 0.025, digits = 5, legend.cex = .9,shade.col="gray",...)

shade.chi(x = NULL, from = NULL, to = NULL, nu = 1, tail = "lower", 
show.p = TRUE, show.d = FALSE, show.dist = TRUE, prob.to.each.tail = 0.025, 
digits = 5,legend.cex = .9,shade.col="gray",...)

shade.bin(x=NULL,from=NULL,to=NULL,n=1,p=0.5,tail="X=x",show.p=TRUE,
show.dist=TRUE, show.d=FALSE,legend.cex = .9,digits=5, ...)

shade.poi(x=NULL,from=NULL,to=NULL,lambda=5,tail="X=x",show.p=TRUE,
show.dist=TRUE, show.d=FALSE,legend.cex = .9,digits=5, ...)

shade.wei(x = NULL, from = NULL, to = NULL, theta = 1, beta = 1, tail = "lower", 
show.p = TRUE, show.d = FALSE, show.dist = TRUE, prob.to.each.tail = 0.025, 
digits = 5, legend.cex = 0.9, shade.col = "gray", ...)

Arguments

x	A quantile, i.e. X = x, or if tail = "two.custom" ins shade.norm, a two element vector specifying the upper bound of the lower tail and the lower bound of the upper tail.
from	To be used with tail = "middle"; the value a in P(a < X < b).
to	To be used with tail = "middle"; the value b in P(a < X < b).
sigma	Standard deviation for the nomral distribution.
mu	Mean of the normal distribution.
tail	One of four possibilities: "lower" provides lower tail shading, "upper" provides upper tail shading, "two" provides two tail shading, and "middle" provide shading in the middle of the pdf, between "from" and "to". The additional option "two.custom" is allowed for shade.norm and shade.t. This allows calculation of asymmetric two tailed probabilities. It requires that the argument x is a two element vector with elements denoting the upper bound of the lower tail and the lower bound of the upper tail. For discrete pdfs (binomial and Poisson) the possibility "X=x" is also allowed, and will be equivalent to the density. Two tailed probability is not implemented for shade.poi.
show.p	Logical; indicating whether probabilities are to be shown.
show.d	Logical; indicating whether densities are to be shown.
show.dist	Logical; indicating whether parameters for the distribution are to be shown.
nu	Degrees of freedom.
nu1	Numerator degrees of freedom for the F-distribution.
nu2	Denominator degrees of freedom for the F-distribution.
prob.to.each.tail	Probability to be apportioned to each tail in the F and Chi-square distributions if tail = "two".
digits	Number of digits to be reported in probsabilities and densities.
n	The number of trials for the binomial pdf.
p	The binomial probability of success.
lambda	The Poisson parameter (i.e. rate).
legend.cex	Character expansion for legends in plots.
shade.col	Color of probability shading.
theta	Pdf parameter.
beta	Pdf parameter.
...	Additional arguments to plot.

Value

Returns a plot with the requested pdf and probability shading.

Note

Lower-tailed chi-squared probabilities are not plotted correctly for df < 3.

Author(s)

Ken Aho

Examples

## Not run: 
##normal
shade.norm(x=1.2,sigma=1,mu=0,tail="lower")
shade.norm(x=1.2,sigma=1,mu=0,tail="upper")
shade.norm(x=1.2,sigma=1,mu=0,tail="two")
shade.norm(from=-.4,to=0,sigma=1,mu=0,tail="middle")
shade.norm(from=0,to=0,sigma=1,mu=0,tail="middle")
shade.norm(x=c(-0.2, 2),sigma=1,mu=0,tail="two.custom")

##t
shade.t(x=-1,nu=5,tail="lower")
shade.t(x=-1,nu=5,tail="upper")
shade.t(x=-1,nu=5,tail="two")
shade.t(from=.5,to=.7,nu=5,tail="middle")
                                                                                        
##F
shade.F(x=2,nu1=15,nu2=8,tail="lower")
shade.F(x=2,nu1=15,nu2=8,tail="upper")
shade.F(nu1=15,nu2=8,tail="two",prob.to.each.tail=0.025)
shade.F(from=.5,to=.7,nu1=15,nu2=10,tail="middle")

##Chi.sq
shade.chi(x=2,nu=5,tail="lower")
shade.chi(x=2,nu=5,tail="upper")
shade.chi(nu=7,tail="two",prob.to.each.tail=0.025)
shade.chi(from=.5,to=.7,nu=5,tail="middle")

##binomial
shade.bin(x=5,n=20,tail="X=x",show.d=TRUE)
shade.bin(x=5,n=20,tail="lower")
shade.bin(x=5,n=20,tail="two")
shade.bin(from=8,to=12,n=20,tail="middle")

##Poisson
shade.poi(x=5,lambda=6,tail="X=x",show.d=TRUE)
shade.poi(x=5,lambda=7,tail="lower")
shade.poi(x=5,lambda=8,tail="upper")
shade.poi(from=8,to=12,lambda=7,tail="middle")

## End(Not run)

asbio documentation built on May 29, 2024, 5:57 a.m.