CATT: The Cochran-Armitage Trend Test

In CATT: The Cochran-Armitage Trend Test

Description

This function conducts the Cochran-Armitage trend test to a 2 by k contingency table. It will report the test statistic (Z) and p-value. A linear trend in the frequencies will be calculated, because the weights (0,1,2) will be used by default.

Usage

CATT(binomial,ordinal,table)

Arguments

ordinal	the vector of the ordinal variable
binomial	the vector of the binomial variable
table	option, the contingency table of table(binomial,ordinal)

Value

Z	the test statistic
p.value	the p value of the hypothesis test

Note

Please feel free to contact us, if you have any advice and find any bug!

Reference:

1. Cochran, WG (1954). Some methods for strengthening the common chi-squared tests. Biometrics. International Biometric Society. 10 (4): 417-451.

2. Armitage, P (1955). Tests for Linear Trends in Proportions and Frequencies. Biometrics. International Biometric Society. 11 (3): 375-386.

Update:

Version 0.2.0: The p value of two side was specified.

Author(s)

Zhicheng Du<[e-mail]>, Yuantao Hao<[e-mail]>

Examples

# type of data is variable
binomial=c(rep(0,20),rep(1,10),rep(0,20),rep(1,20),rep(0,20),rep(1,30))
ordinal=c(rep(0,30),rep(1,40),rep(2,50))
CATT(binomial=binomial,ordinal=ordinal)

# type of data is table
tbl=matrix(c(20,10,20,20,20,30),nrow=2)
CATT(table=tbl)

Example output

	The Cochran-Armitage Trend Test

data:  The type of data is variable!
Z = -2.284, p-value = 0.0224


	The Cochran-Armitage Trend Test

data:  The type of data is table!
Z = -2.284, p-value = 0.0224

CATT documentation built on May 2, 2019, 1:27 p.m.