medianAllPairsTest {PMCMRplus} | R Documentation |
Brown-Mood All Pairs Median Test
Description
Performs Brown-Mood All Pairs Median Test.
Usage
medianAllPairsTest(x, ...)
## Default S3 method:
medianAllPairsTest(x, g, p.adjust.method = p.adjust.methods, ...)
## S3 method for class 'formula'
medianAllPairsTest(
formula,
data,
subset,
na.action,
p.adjust.method = p.adjust.methods,
...
)
Arguments
x |
a numeric vector of data values, or a list of numeric data vectors. |
... |
further arguments to be passed to or from methods. |
g |
a vector or factor object giving the group for the
corresponding elements of |
p.adjust.method |
method for adjusting p values
(see |
formula |
a formula of the form |
data |
an optional matrix or data frame (or similar: see
|
subset |
an optional vector specifying a subset of observations to be used. |
na.action |
a function which indicates what should happen when
the data contain |
Details
For all-pairs comparisons in an one-factorial layout
with non-normally distributed residuals Brown-Mood
non-parametric Median test
can be performed. A total of m = k(k-1)/2
hypotheses can be tested. The null hypothesis
H_{ij}: \mu_i(x) = \mu_j(x)
is tested in the two-tailed test
against the alternative
A_{ij}: \mu_i(x) \ne \mu_j(x), ~~ i \ne j
.
In this procedure the joined median is used for classification,
but pairwise Pearson Chisquare-Tests are conducted. Any method
as given by p.adjust.methods
can be used
to account for multiplicity.
Value
A list with class "PMCMR"
containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimated quantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-value adjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Brown, G.W., Mood, A.M., 1951, On Median Tests for Linear Hypotheses, in: Proceedings of the Second Berkeley Symposium on Mathematical Statistics and Probability. University of California Press, pp. 159–167.
See Also
Examples
## Data set InsectSprays
## Global test
kruskalTest(count ~ spray, data = InsectSprays)
## Conover's all-pairs comparison test
## single-step means Tukey's p-adjustment
ans <- kwAllPairsConoverTest(count ~ spray, data = InsectSprays,
p.adjust.method = "single-step")
summary(ans)
## Dunn's all-pairs comparison test
ans <- kwAllPairsDunnTest(count ~ spray, data = InsectSprays,
p.adjust.method = "bonferroni")
summary(ans)
## Nemenyi's all-pairs comparison test
ans <- kwAllPairsNemenyiTest(count ~ spray, data = InsectSprays)
summary(ans)
## Brown-Mood all-pairs median test
ans <- medianAllPairsTest(count ~ spray, data = InsectSprays)
summary(ans)