Making Functions

> std.dev <- function(x) 
  {
    std.x <- sqrt(var(x));
    std.x;
  }  

> t.stat <- function(x) 
  {
    n <- length(x)
    t <- sqrt(n)*(mean(x)-mu)/std.dev(x)
    list(t=t, p=2*(1- pt(abs(x), n-1)))    
  }  

> unlist(t.stat(z,1))