nag_sparse_nsym_precon_ilu_solve (f11dbc) Example Program Data
  4                    : n
 11                    : nnz
  1.    1    2
  1.    1    3
 -1.    2    1
  2.    2    3
  2.    2    4
  3.    3    1
 -2.    3    4
  1.    4    1
 -2.    4    2
  1.    4    3
  1.    4    4         : a[i], irow[i], icol[i], i=0,...,nnz-1
  5.0  13.0 -5.0  4.0  : y[i], i=0,...,n-1