jmv (version 2.7.0)

anovaNP: One-Way ANOVA (Non-parametric)

Description

The Kruskal-Wallis test is used to explore the relationship between a continuous dependent variable, and a categorical explanatory variable. It is analagous to ANOVA, but with the advantage of being non-parametric and having fewer assumptions. However, it has the limitation that it can only test a single explanatory variable at a time.

Usage

anovaNP(data, deps, group, es = FALSE, pairs = FALSE,
  pairsDunn = FALSE, formula)

Value

A results object containing:

results$table					a table of the test results
results$comparisons					an array of pairwise comparison tables
results$comparisonsDunn					an array of pairwise comparison tables

Tables can be converted to data frames with asDF or as.data.frame. For example:

results$table$asDF

as.data.frame(results$table)

Arguments

data

the data as a data frame

deps

a string naming the dependent variable in data

group

a string naming the grouping or independent variable in data

es

TRUE or FALSE (default), provide effect-sizes

pairs

TRUE or FALSE (default), perform pairwise comparisons

pairsDunn

TRUE or FALSE (default), perform pairwise comparisons

formula

(optional) the formula to use, see the examples

Examples

data('ToothGrowth')

anovaNP(formula = len ~ dose, data=ToothGrowth)

#
#  ONE-WAY ANOVA (NON-PARAMETRIC)
#
#  Kruskal-Wallis
#  -------------------------------
#           X²      df    p
#  -------------------------------
#    len    40.7     2    < .001
#  -------------------------------
#