pi <- 4*atan(1)

letters <- c("a","b","c","d","e","f","g","h","i","j","k","l", "m",
	     "n","o","p","q","r","s","t","u","v","w","x","y","z")

LETTERS <- c("A","B","C","D","E","F","G","H","I","J","K","L", "M",
	     "N","O","P","Q","R","S","T","U","V","W","X","Y","Z")

month.name <-
    c("January", "February", "March", "April", "May", "June",
      "July", "August", "September", "October", "November", "December")

month.abb <- c("Jan", "Feb", "Mar", "Apr", "May", "Jun",
	       "Jul", "Aug", "Sep", "Oct", "Nov", "Dec")