library(vcd)
data("UCBAdmissions")
UCB <- aperm(UCBAdmissions, c(2,1,3))
# marginal table, collapsing over Dept
(UCB2 <- margin.table(UCB, c(1,2)))
## Admit
## Gender Admitted Rejected
## Male 1198 1493
## Female 557 1278
Chisquare test
chisq.test(UCB2)
##
## Pearson's Chi-squared test with Yates' continuity correction
##
## data: UCB2
## X-squared = 91.61, df = 1, p-value < 2.2e-16
Fourfold plots
fourfold(UCB2)
# unstandardized version
fourfold(UCB2, std="ind.max")
fourfold(UCB, mfrow=c(2,3))
woolf_test(UCB)
##
## Woolf-test on Homogeneity of Odds Ratios (no 3-Way assoc.)
##
## data: UCB
## X-squared = 17.902, df = 5, p-value = 0.003072
oddsratio(UCBAdmissions, log=FALSE)
## odds ratios for Admit and Gender by Dept
##
## A B C D E F
## 0.3492120 0.8025007 1.1330596 0.9212838 1.2216312 0.8278727
# plot log odds ratios
plot(oddsratio(UCBAdmissions), xlab="Department", ylab="Log Odds Ratio (Admit|Gender)")