Bayes.R

#Bayes Theorem
cancer <- sample(c('No','Yes'), size=1000, replace=TRUE, prob=c(0.99852,0.00148))
test <- rep(NA, 1000) # creating a dummy variable 
test[cancer=='No'] <- sample(c('Negative','Positive'), size=sum(cancer=='No'), replace=TRUE, prob=c(0.99,0.01))
test[cancer=='Yes'] <- sample(c('Negative','Positive'), size=sum(cancer=='Yes'), replace=TRUE, prob=c(0.07, 0.93))


P_cancer_and_pos<-0.00148*0.93
P_no_cancer_and_pos<-0.99852*0.01

Bayes_Theorem<-(P_cancer_and_pos/(P_cancer_and_pos+P_no_cancer_and_pos))
Bayes_Theorem