F.curve: plot a chisquare or a F-curve.

In HH: Statistical Analysis and Data Display: Heiberger and Holland

plot a chisquare or a F-curve.

Description

Plot a chisquare or a F-curve. Shade a region for rejection region or do-not-reject region. F.observed and chisq.observed plots a vertical line with arrowhead markers at the location of the observed xbar and outlines the area corresponding to the p-value.

Usage

F.setup(df1=1,
        df2=Inf,
        ncp=0,
        log.p=FALSE,
        xlim.in=c(0, 5),
        ylim.in=range(c(0, 1.1*df.intermediate(x=seq(.5,1.5,.01),
                       df1=df1, df2=df2, ncp=ncp, log=log.p))),
        main.in=main.calc, ylab.in="F density",
        ...)

F.curve(df1=1,
        df2=Inf,
        ncp=0,
        log.p=FALSE,
        alpha=.05,
        critical.values=f.alpha,
        f=seq(0, par()$usr[2], length=109),
        shade="right", col=par("col"),
        axis.name="f",
        ...)

F.observed(f.obs, col="green",
           df1=1,
           df2=Inf,
           ncp=0,
           log.p=FALSE,
           axis.name="f",
           shade="right",
           shaded.area=0,
           display.obs=TRUE)

chisq.setup(df=1,
           ncp=0,
           log.p=FALSE,
           xlim.in=c(0, qchisq.intermediate(p=1-.01, df=df, ncp=ncp, log.p=log.p)),
           ylim.in=range(c(0, 1.1*dchisq.intermediate(x=seq(max(0.5,df-2),df+2,.01),
                         df=df, ncp=ncp, log=log.p))),
           main.in=main.calc, ylab.in="Chisq density",
           ...)

chisq.curve(df=1,
            ncp=0,
            log.p=FALSE,
            alpha=.05,
            critical.values=chisq.alpha,
            chisq=seq(0, par()$usr[2], length=109),
            shade="right", col=par("col"),
            axis.name="chisq",
            ...)

chisq.observed(chisq.obs, col="green",
               df=1,
               ncp=0,
               log.p=FALSE,
               axis.name="chisq",
               shade="right",
               shaded.area=0,
               display.obs=TRUE)

Arguments

xlim.in, ylim.in	Initial settings for xlim, ylim. The defaults are calculated for the degrees of freedom.
df, df1, df2, ncp, log.p	Degrees of freedom, non-centrality parameter, probabilities are given as log(p). See pchisq and pf.
alpha	Probability of a Type I error. alpha is a vector of one or two values. If one value, it is the right alpha. If two values, they are the c(left.alpha, right.alpha).
critical.values	Critical values. Initial values correspond to the specified alpha levels. A scalar value implies a one-sided test on the right side. A vector of two values implies a two-sided test.
main.in, ylab.in	Main title, default ylab.
shade	Valid values for shade are "right", "left", "inside", "outside", "none". Default is "right" for one-sided critical.values and "outside" for two-sided critical values.
col	color of the shaded region and the area of the shaded region.
shaded.area	Numerical value of the area. This value may be cumulated over two calls to the function (one call for left, one call for right). The shaded.area is the return value of the function. The calling program is responsible for the cumulation.
display.obs	Logical. If TRUE, print the numerical value of the observed value, plot a vertical abline at the value, and use it for showing the p-value. If FALSE, don't print or plot the observed value; just use it for showing the p-value.
f, chisq	Values used to draw curve. Replace them if more resolution is needed.
f.obs, chisq.obs	Observed values of statistic. p-values are calculated for these values.
axis.name	Axis name.
...	Other arguments which are ignored.

Author(s)

Richard M. Heiberger <[e-mail]>

Examples

old.omd <- par(omd=c(.05,.88, .05,1))
chisq.setup(df=12)
chisq.curve(df=12, col='blue')
chisq.observed(22, df=12)
par(old.omd)

old.omd <- par(omd=c(.05,.88, .05,1))
chisq.setup(df=12)
chisq.curve(df=12, col='blue', alpha=c(.05, .05))
par(old.omd)

old.omd <- par(omd=c(.05,.88, .05,1))
F.setup(df1=5, df2=30)
F.curve(df1=5, df2=30, col='blue')
F.observed(3, df1=5, df2=30)
par(old.omd)

old.omd <- par(omd=c(.05,.88, .05,1))
F.setup(df1=5, df2=30)
F.curve(df1=5, df2=30, col='blue', alpha=c(.05, .05))
par(old.omd)

HH documentation built on May 29, 2024, 6:24 a.m.