sigma2.test: Test of a variance

In TRSbook: Functions and Datasets to Accompany the Book "The R Software: Fundamentals of Programming and Statistical Analysis"

Description

Comparing the theoretical variance with a reference value

Usage

sigma2.test(x, alternative = "two.sided", var0 = 1, conf.level = 0.95)

Arguments

x	numeric vector
alternative	Alternative hypothesis for the test. Either two sided ("two.sided"), one sided to the left ("less") or one sided to the right ("greater"). Default is "two.sided".
var0	value of reference for the variance
conf.level	confidence level

Value

Returns a list:

statistic	Value of the test statistic
parameter	degrees of freedom
p.value	p-value of the test
conf.int	confidence interval
estimate	sample variance
null.value	value of reference for the variance
alternative	Alternative hypothesis for the test
method	"One-sample Chi-squared test for given variance"
data.name	name of the data set

Author(s)

Lafaye de Micheaux Pierre <[e-mail]>, Remy Drouilhet <[e-mail]>, Liquet Benoit <[e-mail]>

References

Chapter 13 (Confidence Intervals and Hypothesis Testing) from the book: The R Software, Fundamentals of Programming and Statistical Analysis

Examples

data(NUTRIELDERLY)
sigma2.test(NUTRIELDERLY$weight,conf.level=0.9)$conf

Example output

Loading required package: xtable
Loading required package: RColorBrewer
Loading required package: gdata
gdata: read.xls support for 'XLS' (Excel 97-2004) files ENABLED.

gdata: read.xls support for 'XLSX' (Excel 2007+) files ENABLED.

Attaching package: 'gdata'

The following object is masked from 'package:stats':

    nobs

The following object is masked from 'package:utils':

    object.size

The following object is masked from 'package:base':

    startsWith

Loading required package: IndependenceTests
[1] 124.8330 170.3277
attr(,"conf.level")
[1] 0.9

TRSbook documentation built on May 2, 2019, 2:45 a.m.