511 classes

pgchisq

R Documentation

Graphical display for the Chi Squared distribution, given a specified quantile

Description

A function to produce a graph of a Chi Squared distribution with regions shaded according to a specified quantile ( Chi Squared value).

Usage

pgchisq(quantile, df = 1)

Arguments

`quantile`	The Chi Squared value to be evaluated, (e.g., 3.84)
`df`	The `df` for the Chi Squared Distribution. Default is 1 df (see note below)

Warning

Specifying extremely high or low quantiles may not yield visible shaded areas if the regions are beyond the limits of the X axis scale of the graph.

Note

The scaling on plots of Chi Squared Distributions of varying degrees of freedom requires considerable adjustment. When df=1, pgchisq returns a two-paneled figure. The plot on the left is a fairly full scale plot of the distribution without shading of a tail region. The plot on the right has axes truncated so that scale expansion will permit visualization of the relevant area under the curve.

Note that the pgchisq function only displays upper tail regions since most inference with the Chi Squared distribution only requires upper tail evaluation. The lower tail probability can be found as 1 minus the returned upper tail probability.

Author(s)

Bruce Dudek bruce.dudek@albany.edu

Examples


pgchisq(3.84,df=1)
pgchisq(4.20,df=2)
pgchisq(30.5,df=25)
pgchisq(200,df=250)
pgchisq(4.75,df=1)
pgchisq(4.75,df=2)
pgchisq(45,df=25)
pgchisq(475,df=250)

bcdudek/bcdstats documentation built on Jan. 3, 2024, 10:09 p.m.