# F.curve

From HH v3.1-42
0th

Percentile

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

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.

Keywords
distribution, hplot, aplot
##### 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),
axis.name="chisq",
...)chisq.observed(chisq.obs, col="green",
df=1,
ncp=0,
log.p=FALSE,
axis.name="chisq",
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.

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.

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.

##### Aliases
• chisq.curve
• chisq.observed
• chisq.setup
• F.curve
• F.observed
• F.setup
##### Examples
# NOT RUN {
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)

# }

Documentation reproduced from package HH, version 3.1-42, License: GPL (>= 2)

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