A is obtained with MatCopy(,,DIFFERENT_NONZERO_PATTERN):
  type: seqaij
  rows=10, cols=10
  total: nonzeros=28, allocated nonzeros=200
  total number of mallocs used during MatSetValues calls =10
    not using I-node routines

A is obtained with MatCopy(,,SAME_NONZERO_PATTERN):
  type: seqaij
  rows=10, cols=10
  total: nonzeros=28, allocated nonzeros=28
  total number of mallocs used during MatSetValues calls =0
    not using I-node routines
A:
  type: seqaij
row 0: (0, 2.)  (1, -1.) 
row 1: (0, -1.)  (1, 2.)  (2, -1.) 
row 2: (1, -1.)  (2, 2.)  (3, -1.) 
row 3: (2, -1.)  (3, 2.)  (4, -1.) 
row 4: (3, -1.)  (4, 2.)  (5, -1.) 
row 5: (4, -1.)  (5, 2.)  (6, -1.) 
row 6: (5, -1.)  (6, 2.)  (7, -1.) 
row 7: (6, -1.)  (7, 2.)  (8, -1.) 
row 8: (7, -1.)  (8, 2.)  (9, -1.) 
row 9: (8, -1.)  (9, 2.) 
