#This generates all possible subsets of size 2 when $n=4$.
combn(c(1:4),2)

#Writing own function for p-value of signed rank test
signrank<-function(n,T){
  x<-c(1:n)
  k<-0
  for(i in 1:n){
    y<-combn(x,i)
    l<-dim(y)[2]
    for(j in 1:l){
      k<-cbind(k,sum(x[y[,j]]))}
  }
  pval<-length(which(k>=T))/length(k)
  return(pval)
}
table(k)
#Signed rank test for the example done in class
a<-c(73, 82, 87, 68, 106, 60,97)
b<-a-70
r<-rank(abs(b))
s<-ifelse(b>0,1,0)
T<-sum(r*s)
signrank(7,T)

# Directly using built-in function for signed rank test
library(stats)
wilcox.test(a,mu=70,alternative="greater")