Permutation test for ANOVA F-test — permTestAnova • CarletonStats

Permutation test to see if the population mean is the same for two or more populations. For instance, test \(latex\) where \(latex\) denotes the population mean. The values of the numeric variable are randomly assigned to the groups and the ANOVA F statistic is calculated. The command will print the mean and standard error of the distribution of the test statistic as well as a P-value.

Usage

permTestAnova(x, ...)

# Default S3 method
permTestAnova(
  x,
  group,
  B = 9999,
  plot.hist = TRUE,
  plot.qq = FALSE,
  xlab = NULL,
  ylab = NULL,
  title = NULL,
  seed = NULL,
  ...
)

# S3 method for class 'formula'
permTestAnova(formula, data = parent.frame(), subset, ...)

Arguments

x: a numeric vector.
...: further arguments to be passed to or from methods.
group: a factor variable with two or more levels. If group is a numeric vector, it will be coerced into a factor variable.
B: the number of resamples (positive integer greater than 2).
plot.hist: a logical value. If TRUE, the permutation distribution of the statistic is plotted.
plot.qq: a logical value. If TRUE, then a normal quantile-quantile plot of the resampled test statistic is created.
xlab: an optional character string for the x-axis label
ylab: an optional character string for the y-axis label
title: an optional character string giving the plot title
seed: optional argument to set.seed
formula: a formula of the form y ~ group where y is numeric and group is a factor variable.
data: a data frame with the variables in the formula.
subset: an optional expression specifying which observations to keep.

Value

Returns invisibly a vector of the replicates of the test statistic.

Details

Observations with missing values are removed.

Methods (by class)

permTestAnova(default): Permutation test for ANOVA F-test
permTestAnova(formula): Permutation test for ANOVA F-test

References

Tim Hesteberg's website: https://www.timhesterberg.net/bootstrap-and-resampling

Author

Adam Loy, Laura Chihara

Examples


permTestAnova(states03$ViolentCrime, states03$Region, B = 499)
#> 
#> 	** Permutation test **
#> 
#>  Permutation test with alternative: greater 
#>  Observed F statistic: 1.82174 
#>  Mean of permutation distribution: 1.08794 
#>  Standard error of permutation distribution: 0.98715 
#>  P-value:   0.154 
#> 
#> 	*-------------*
#> 


#using formula syntax
if (FALSE) { # \dontrun{
permTestAnova(ViolentCrime ~ Region, data = states03, B = 9999)
} # }