Use of Subroutine VFILL

The array U(*) should contain an initial approximation to the solution of the linear system before any ITPACKV module is called. If the user has no information for making such a guess, then the zero vector may be used as the starting vector. The subroutine VFILL() can be used to fill a vector with a constant. For example,

CALL VFILL (N, U, VAL)

fills the array U(*) of length N with the value VAL in each entry.