[petsc-users] VecGetOwnershipRanges

[Satish Balay]

On Tue, 16 Apr 2013, Hui Zhang wrote:

> VecGetOwnershipRanges(Vec x,const PetscInt *ranges[])
> 
> From the html manual page,
> 
> range -array of length size+1 with the start and end+1 for each process 
> 
> Is it PetscInt ranges[size+1][2] or PetscInt ranges[size+1]?

Its ranges[size+1]

If you a vec of len 10 - distrbuted across 3 procs - say 
proc-0 3
proc-1 3
proc-2 4

Then you have ranges[3+1] = {0,3,6,10}

Satish

> 
> The function calls
> 
> PetscLayoutGetRanges(PetscLayout map,const PetscInt *range[])
> 
> for which the manual page says
> 
> range -start of each processors range of indices (the final entry is one more then the last index on the last process) 
> 
> I'm sorry that I'm confused.