[petsc-users] about VecScatterCreate()

[Yujie]

Dear PETSc Developers,

I got the following information from VecScatterCreate() manpage.
"
PetscErrorCode  VecScatterCreate(Vec xin,IS ix,Vec yin,IS iy,VecScatter *newctx)

Collective on Vec

Input Parameters
	xin 	- a vector that defines the shape (parallel data layout of the
vector) of vectors from which we scatter
	yin 	- a vector that defines the shape (parallel data layout of the
vector) of vectors to which we scatter
	ix 	- the indices of xin to scatter (if PETSC_NULL scatters all values)
	iy 	- the indices of yin to hold results (if PETSC_NULL fills entire
vector yin)
"
My question is about "ix". If xin and yin are parallel Vec, how about ix?

Is "ix"  an IS only containing local index set or a parallel IS
containing all the index set on all the processors (each local index
set on its processor)? Thanks a lot.

Regards,
Yujie