| mwu {sjstats} | R Documentation |
This function performs a Mann-Whitney-U-Test (or Wilcoxon rank sum test,
see wilcox.test and wilcox_test)
for x, for each group indicated by grp. If grp
has more than two categories, a comparison between each combination of
two groups is performed.
The function reports U, p and Z-values as well as effect size r
and group-rank-means.
mwu(x, grp, distribution = "asymptotic", weight.by = NULL, out = c("txt",
"viewer", "browser"))
x |
Numeric vector or variable. |
grp |
Grouping variable indicating the groups that should be used for comparison. |
distribution |
Indicates how the null distribution of the test statistic should be computed.
May be one of |
weight.by |
Vector of weights that will be applied to weight all observations.
Must be a vector of same length as the input vector. Default is
|
out |
Character vector, indicating whether the results should be printed
to console ( |
(Invisibly) returns a data frame with U, p and Z-values for each group-comparison as well as effect-size r; additionally, group-labels and groups' n's are also included.
This function calls the wilcox_test with formula. If grp
has more than two groups, additionally a Kruskal-Wallis-Test (see kruskal.test)
is performed.
Interpretation of effect sizes, as a rule-of-thumb:
small effect >= 0.1
medium effect >= 0.3
large effect >= 0.5
data(efc) # Mann-Whitney-U-Tests for elder's age by elder's dependency. mwu(efc$e17age, efc$e42dep)