powerAnalysis (version 0.2.1)

ES.chisq.assoc: Compute effect size of chi-squared test of association

Description

Compute effect size of chi-squared test of association

Usage

ES.chisq.assoc(ct = NULL, chisq = NULL, p = NULL, n = NULL, df = NULL, mindf = NULL)

Arguments

ct

a m x n Contingency Table (matrix with m rows and n columes)

chisq

the value the chi-squared test statistic

p

p value for the chi-squared test

n

total number of observations (sample size)

df

degree of freedom (e.g., df=(m-1)*(n-1))

mindf

the degrees of freedom for the variable with the smaller number of levels, if m > n, mindf=n-1, otherwise, mindf=m-1

See Also

ES.chisq.gof

Examples

counts <- matrix(c(225,125,85,95),nrow=2,byrow=TRUE)
ES.chisq.assoc(ct=counts)

case <- c(225,85,100)
control <- c(125,95,125)
counts <- cbind(case,control)
ES.chisq.assoc(ct=counts)

p1 <- c(225,85,100)
p2 <- c(125,95,125)
p3 <- c(175,90,113)
counts <- cbind(p1,p2,p3)
ES.chisq.assoc(ct=counts)

ES.chisq.assoc(chisq=13.561,n=530,df=1,mindf=1)

ES.chisq.assoc(p=0.000231,n=530,df=1,mindf=1)