HH: F.curve – R documentation

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F.curve

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 <rmh@temple.edu>

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

Statistical Analysis and Data Display: Heiberger and Holland

v3.1-43

GPL (>= 2)

Authors

Richard M. Heiberger

Initial release

2020-11-27