> a <- runif(100)
> cut(a, seq(from = 0, to = 1, by = 0.2))
  [1] (0,0.2]   (0.8,1]   (0.8,1]   (0.6,0.8] (0.6,0.8] (0,0.2]   (0.6,0.8]
  [8] (0.2,0.4] (0.8,1]   (0.4,0.6] (0.8,1]   (0.4,0.6] (0.8,1]   (0.6,0.8]
 [15] (0.8,1]   (0,0.2]   (0.8,1]   (0.8,1]   (0.6,0.8] (0.6,0.8] (0.2,0.4]
 [22] (0.4,0.6] (0.6,0.8] (0.2,0.4] (0.6,0.8] (0.6,0.8] (0.6,0.8] (0,0.2]  
 [29] (0,0.2]   (0.2,0.4] (0,0.2]   (0,0.2]   (0,0.2]   (0,0.2]   (0,0.2]  
 [36] (0.6,0.8] (0.2,0.4] (0.6,0.8] (0.6,0.8] (0.8,1]   (0.2,0.4] (0.4,0.6]
 [43] (0.4,0.6] (0.6,0.8] (0.2,0.4] (0.6,0.8] (0.6,0.8] (0.6,0.8] (0.4,0.6]
 [50] (0.6,0.8] (0.6,0.8] (0,0.2]   (0.2,0.4] (0.8,1]   (0.8,1]   (0.8,1]  
 [57] (0.6,0.8] (0.2,0.4] (0.2,0.4] (0,0.2]   (0.8,1]   (0.8,1]   (0.2,0.4]
 [64] (0.8,1]   (0.2,0.4] (0.4,0.6] (0.8,1]   (0,0.2]   (0.4,0.6] (0,0.2]  
 [71] (0.4,0.6] (0.8,1]   (0.6,0.8] (0.4,0.6] (0,0.2]   (0.2,0.4] (0.4,0.6]
 [78] (0,0.2]   (0.2,0.4] (0.8,1]   (0,0.2]   (0.4,0.6] (0.8,1]   (0,0.2]  
 [85] (0,0.2]   (0.2,0.4] (0.2,0.4] (0.4,0.6] (0.8,1]   (0.2,0.4] (0,0.2]  
 [92] (0.6,0.8] (0.2,0.4] (0.2,0.4] (0.8,1]   (0.2,0.4] (0.4,0.6] (0,0.2]  
 [99] (0,0.2]   (0,0.2]  
Levels: (0,0.2] (0.2,0.4] (0.4,0.6] (0.6,0.8] (0.8,1]