#### Example: French skiers #### Here is one way to read the data vector of values with labels for the table ski<-matrix(c(3, 11, 2, 12), ncol=2, dimnames=list(Treatment=c("Placebo", "VitaminC"), Cold=c("Cold", "NoCold"))) ski #### Let us look at the Percentage, Row Percentage and Column Percentages #### of the total observations contained in each cell. Percentage=100*ski/sum(ski) RowSums=rowSums(ski) RowPercentage=100*rbind(ski[1,]/RowSums[1],ski[2,]/RowSums[2]) ColSums=colSums(ski) ColPercentage=100*cbind(ski[,1]/ColSums[1],ski[,2]/ColSums[2]) Percentage RowPercentage ColPercentage #### Pearson's Chi-squared test with Yates' continuity correction result<-chisq.test(ski) result #### Let's look at the obseved, expected values and the residuals result\$observed result\$expected result\$residuals #### Pearson's Chi-squared test WITHOUT Yates' continuity correction result<-chisq.test(ski, correct=FALSE) result result\$observed result\$expected result\$residuals #### Likelihood Ratio Chi-Squared Statistic chisq=1-pchisq(2*sum(ski*log(ski/result\$expected)),df=1) chisq #### Fisher's Exact Test Fisher_Exact_TwoSided=fisher.test(ski,alternative = "two.sided") Fisher_Exact_Less=fisher.test(ski,alternative = "less") Fisher_Exact_Greater=fisher.test(ski,alternative = "greater") rbind(Fisher_Exact_TwoSided,Fisher_Exact_Less,Fisher_Exact_Greater)