SsTest: Shan, Young and Kang's S Test

In npordtests: Nonparametric Tests for Equality of Location Against Ordered Alternatives

Description

SsTest performs S test.

Usage

SsTest(formula, data, alpha = 0.05, na.rm = TRUE, verbose = TRUE)

Arguments

formula	a formula of the form lhs ~ rhs where lhs gives the sample values and rhs the corresponding groups.
data	a data frame containing the variables in the formula formula
alpha	the level of significance to assess the statistical difference. Default is set to alpha = 0.05.
na.rm	a logical value indicating whether NA values should be stripped before the computation proceeds.
verbose	a logical for printing output to R console.

Value

A list with class "owt" containing the following components:

statistic	the S test statistic.
mean	the mean of the S test statistic.
variance	the variance of the S test statistic.
Z	the standardized test statistic.
p.value	the p-value of the test.
alpha	the level of significance.
method	the character string "S test".
data	a data frame containing the variables in which NA values (if exist) are removed.
formula	a formula of the form lhs ~ rhs where lhs gives the sample values and rhs the corresponding groups.

Author(s)

Bulent Altunkaynak

References

Jonckheere, A. R. (1954). A Distribution-Free k-Sample Test Against Ordered Alternatives. Biometrika, 41, 133-145.

Shan, G., Young, D., Kang, L.(2014). A New Powerful Nonparametric Rank Test for Ordered Alternative Problem. Plos One, 9:11, 1-10.

Examples

library(npordtests)

## Data from Jonckheere (1954)
data(jdata)
SsTest(Y~X,jdata)

## Data from Lehmann (1975)
data(lehmann)
SsTest(Values~Group,lehmann)

npordtests documentation built on Oct. 30, 2019, 11:35 a.m.