 rray [,1,50][1]  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15...
 @ dim     : int [1:3] 1 1 50
 @ dimnames:List of 3
  ..$ : NULL
  ..$ : NULL
  ..$ : NULL
