Perform Fligner-Killeen test for homogeneity of variances¶

Source: man/performFlignerKilleenTest.Rd · Help: ?performFlignerKilleenTest

Non-parametric test based on ranks.

Usage¶

performFlignerKilleenTest(model, data = NULL, group)

Arguments¶

model: an object of class lm.
data: data frame used to fit model. When NULL, the default, the model frame of model is used, so group must then be a variable of the model. The model frame holds the terms of the model rather than its variables (log(x) rather than x), so a model that transforms a variable needs data, as does a model with an offset() term.
group: name of the grouping variable.

Value¶

An object of class htest containing the chi-squared statistic, p-value and degrees of freedom.

Details¶

Absolute residuals are ranked after adjusting for group medians. The statistic approximates a chi-square distribution with \(k-1\) degrees of freedom.

References¶

Fligner, M. A., & Killeen, T. J. (1976). Distribution-free two-sample tests for scale. Journal of the American Statistical Association, 71(353), 210–213.

Examples¶

 data(mtcars)
 mtcars$cyl <- factor(mtcars$cyl)
 m <- lm(mpg ~ wt, data = mtcars)
 performFlignerKilleenTest(m, mtcars, "cyl")