Package 'wilcoxmed'

Title: Computes Values for the 1-Sample Wilcoxon Sign Rank Test for Medians
Description: An implementation of the 1-Sample Wilcoxon Sign rank test for medians. It includes 2 functions, W_stat(), which computes the exact probabilities of the Wilcoxon Sign Rank Test Statistic, W. The second function, Wilcox.m.test() allows the user to conduct the 1-Sample Wilcoxon Sign Rank hypothesis test for medians, this also allows the user to conduct the hypothesis test for the normal approximation.
Authors: Dion Kwan [aut, cre]
Maintainer: Dion Kwan <[email protected]>
License: GPL-2
Version: 0.0.1
Built: 2025-02-17 04:29:11 UTC
Source: https://github.com/dkzk96/wilcoxmed

Help Index


Wilcoxon Sign Rank Test Statistic Exact Distribution

Description

This function allows the user to find the probability values from the exact distribution of W, Bickel and Doksum(1973). The exact P(W=x), P(W<=x), P(W>=x) values is found via an exhaustive enumeration of the possible permutations of data with size n.

Usage

W_stat(n , test_stat, side = c('geq','leq','eq'))

Arguments

n

Size of data or Number of observations

test_stat

The x value specified in P(W=x), P(W<=x), P(W>=x)

side

The tails of exact probability the user wants to compute e.g. 'eq' = P(W=x), 'leq' = P(W<=x), 'geq' = 'P(W>=x)

Value

The exact probability values as specified.

Examples

W_stat(n=5, test_stat = 3, side = 'leq')

1-Sample Wilcoxon Sign Rank Hypothesis Test for Medians

Description

This function allows the user to conduct the 1-Sample Wilcoxon Sign Rank Hypothesis Test for Medians using the probability values from the exact distribution of W, Bickel and Doksum(1973).

Usage

Wilcox.m.test(dat, m_h0, alpha = 0.05,
alternative=c('greater', 'lesser', 'noteq'), normal_approx=F)

Arguments

dat

data vector relating to the sample the user is performing the hypothesis test for

m_h0

The value of the median as specified by the null hypothesis H_0

alpha

The significance level of the hypothesis test (default = 0.05)

alternative

The sign of the alternative hypothesis. e.g 'greater' - H_1:m>m_h0 , 'lesser' - H_1:m<m_h0, 'noteq' - H_1:m!=m_h0

normal_approx

Should the normal approximation test be applied? (default = F)

Details

This hypothesis test allows breaking of ties, and the number of ties broken is also reflected in the printed results.

Value

Prints out the results of the tests, and returns 3 values- test statistic, p-value, and the significance level of the test, alpha

See Also

Wilcox.test() for the same tests applied to 2 sample problems but is not able to break ties

Examples

Given some data: 3, 4, 7, 10, 4, 12, 1, 9, 2, 15
If we want to test the hypotheses H_0: m=5 against H_1: m>5
without using normal approximation:
vec = c(3, 4, 7, 10, 4, 12, 1, 9, 2, 15)
res = Wilcox.m.test(dat = vec, m_h0 = 5,
alternative = 'greater', normal_approx = F)

If we want to apply the normal approximation(Z-test), with the same hypotheses:
res = Wilcox.m.test(dat = vec, m_h0 = 5,
alternative = 'greater', normal_approx = T)