install.packages("Hmisc")
library(Hmisc)

########## Which odds ratio? ##########
bc <- matrix(c(4475, 65, 1597, 31), nrow = 2, ncol = 2, byrow = T)
dimnames(bc) <- list(c("Before age 25", "25 or older"), c("No", "Yes"))
bc

fisher.test(bc)

bc[,2:1]
fisher.test(bc[,2:1])

########## Power ##########

bpower(.01, odds.ratio = 1.5, n1 = 4500, n2 = 1500)

bpower(.35, odds.ratio = 1.5, n1 = 150, n2 = 150)
# or
bpower(.35, odds.ratio = 1.5, n = 300)