info = VecCreate(MPI_Comm comm,int m,int M,Vec *x);where comm denotes the MPI communicator. The type of storage for the vector may be set with either calls to VecSetType() or VecSetFromOptions(). Additional vectors of the same type can be formed with
info = VecDuplicate(Vec old,Vec *new);The commands
info = VecSet(Vec X,PetscScalar value); info = VecSetValues(Vec x,int n,int *indices, Scalar *values,INSERT_VALUES);respectively set all the components of a vector to a particular scalar value and assign a different value to each component. More detailed information about PETSc vectors, including their basic operations, scattering/gathering, index sets, and distributed arrays, may be found in the PETSc users manual.