sigmaMenu {RcmdrPlugin.UCA}

Variance test

Description

Within the "Statistics" -> "Variances" menu, a new entry is provided for calculate confidence intervals and make contrasts on variance in a normal population. This option uses the function sigma.test of the package TeachingDemos. For more information see sigma.test.

Details

Here is an example of "Single-Sample Variance Test..." menu entry.

Load data "sweetpotato" selecting from Rcmdr menu: "Data" -> "Data in packages" -> "Read data set from an attached package..." then double-click on "randtests", click on "sweetpotato" and on "OK". Rcmdr reply with the following command in source pane (R Script)

data(sweetpotato, package="randtests")

sweetpotato <- as.data.frame(sweetpotato)

To build a confidence interval for sigma on variable "yield", select from Rcmdr menu: "Statistics" -> "Variances" -> "Single-sample Variance Test..." select "yield" and "OK". Rcmdr reply with the following command in source pane (R Script)

with(sweetpotato, sigma.test(yield[!is.na(yield)], alternative='two.sided', sigmasq=1.0, conf.level=0.95))

Author(s)

Manuel Munoz-Marquez <[e-mail]>

See Also

For more information see Rcmdr-package.

Para ayuda en español, véase Test de varianza (es). (For Spanish help see Test de varianza (es).)