umfpack_test2():
  C version
  Test umfpack().

  The matrix a:

 2.000000 3.000000 0.000000 0.000000 0.000000
 3.000000 0.000000 4.000000 0.000000 6.000000
 0.000000 -1.000000 -3.000000 2.000000 0.000000
 0.000000 0.000000 0.000000 0.000000 0.000000
 0.000000 4.000000 2.000000 0.000000 1.000000

  The right hand side b:

 8.000000
 45.000000
 -3.000000
 3.000000
 19.000000
  Number of nonzero matrix entries = 11

  Ai:
 0
 1
 0
 2
 4
 1
 2
 4
 2
 1
 4

  Ap:
 0
 2
 5
 8
 9
 11

  Ax:
 2
 3
 3
 -1
 4
 4
 -3
 2
 2
 6
 1