F11DB_T1W_F 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, irow, icol
  5.0  13.0 -5.0  4.0   y