cJCK: Computes a critical value for the Jonckheere-Terpstra J...

Description Usage Arguments Value Author(s) References Examples

View source: R/cJCK.R

Description

This function computes the critical value for the Jonckheere-Terpstra J distribution at (or typically in the "Exact" case, close to) the given alpha level. The function takes advantage of Harding's (1984) algorithm to quickly generate the distribution.

Usage

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cJCK(alpha, n, method=NA, n.mc=10000)

Arguments

alpha

A numeric value between 0 and 1.

n

A vector of numeric values indicating the size of each of the k data groups.

method

Either "Exact" or "Asymptotic", indicating the desired distribution. When method=NA, if sum(n)<=200, the "Exact" method will be used to compute the J distribution. Otherwise, the "Asymptotic" method will be used.

n.mc

Not used. Only included for standardization with other critical value procedures in the NSM3 package.

Value

Returns a list with "NSM3Ch6c" class containing the following components:

n

number of observations in the k data groups

cutoff.U

upper tail cutoff at or below user-specified alpha

true.alpha.U

true alpha level corresponding to cutoff.U (if method="Exact")

Author(s)

Grant Schneider

References

Harding, E. F. "An efficient, minimal-storage procedure for calculating the Mann-Whitney U, generalized U and similar distributions." Applied statistics (1984): 1-6.

Examples

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##Hollander-Wolfe-Chicken Example 6.2 Motivational Effect of Knowledge of Performance
cJCK(.0490, c(6,6,6),"Exact")
cJCK(.0490, c(6,6,6),"Monte Carlo")
cJCK(.0231, c(6,6,6),"Exact")

Example output

Loading required package: combinat

Attaching package:combinatThe following object is masked frompackage:utils:

    combn

Loading required package: MASS
Loading required package: partitions
Loading required package: survival
Group sizes: 6 6 6 
For the given alpha=0.049, the upper cutoff value is Jonckheere-Terpstra J=75,
with true alpha level=0.049
Group sizes: 6 6 6 
For the given alpha=0.049, the upper cutoff value is Jonckheere-Terpstra J=75,
with true alpha level=0.049
Warning message:
In cJCK(0.049, c(6, 6, 6), "Monte Carlo") :
  The exact computation will work for large data, so Monte Carlo methods
		    are not recommended for this procedure.
Group sizes: 6 6 6 
For the given alpha=0.0231, the upper cutoff value is Jonckheere-Terpstra J=79,
with true alpha level=0.0231

NSM3 documentation built on April 6, 2021, 5:05 p.m.

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