Steel's k-Treatments vs. Control Test
Performs the non-parametric Steel's test for simultaneously testing k-treatments vs. one control.
steelsKSampleTest(x, ...)
## Default S3 method:
steelsKSampleTest(x, g, alternative = c("two.sided", "greater", "less"), ...)
## S3 method for class 'formula'
steelsKSampleTest(
formula,
data,
subset,
na.action,
alternative = c("two.sided", "greater", "less"),
...
)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 |
alternative |
the alternative hypothesis. Defaults to |
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 |
It tests H: F(i) = F(0), ~ i ≤ k, against A: F(i) > F(0) (greater) with at least one inequality being strict.
The function is a wrapper function that calls Steel.test of
the package kSamples with argument method = "asymptotic".
A list with class "htest" containing the following components:
a character string indicating what type of test was performed.
a character string giving the name(s) of the data.
the estimated quantile of the test statistic.
the p-value for the test.
the parameters of the test statistic, if any.
a character string describing the alternative hypothesis.
the estimates, if any.
the estimate under the null hypothesis, if any.
Scholz, F. and Zhu, A. (2019). kSamples: K-Sample Rank Tests and their Combinations. R package version 1.2-9. https://CRAN.R-project.org/package=kSamples
Steel, R. G. D. (1959) A Multiple Comparison Rank Sum Test: Treatments Versus Control, Biometrics 15, 560–572.
## Example from Sachs (1997, p. 402)
x <- c(106, 114, 116, 127, 145,
110, 125, 143, 148, 151,
136, 139, 149, 160, 174)
g <- gl(3,5)
levels(g) <- c("0", "I", "II")
## Steel's Test
steelsKSampleTest(x ~ g, alternative = "greater")
## Example from USEPA (2002):
## Reproduction data from a Ceriodaphnia dubia
## 7-day chronic test to several concentrations
## of effluent. Dose level 50% is excluded.
x <- c(20, 26, 26, 23, 24, 27, 26, 23, 27, 24,
13, 15, 14, 13, 23, 26, 0, 25, 26, 27,
18, 22, 13, 13, 23, 22, 20, 22, 23, 22,
14, 22, 20, 23, 20, 23, 25, 24, 25, 21,
9, 0, 9, 7, 6, 10, 12, 14, 9, 13,
rep(0,10))
g <- gl(6, 10)
levels(g) <- c("Control", "3%", "6%", "12%", "25%", "50%")
## NOEC at 3%, LOEC at 6%
steelsKSampleTest(x ~ g, subset = g != "50%", alternative = "less")Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.