[petsc-dev] ISLocalToGlobalMappingGetInfo

[Smith, Barry F.]

  There could be a bug. Perhaps check the entries for that "extra" connection, are they all actual meaningful connections. The code that fills up these data structures is somewhat involved.

   Barry


> On Aug 8, 2019, at 9:39 AM, Pierre Jolivet via petsc-dev <petsc-dev at mcs.anl.gov> wrote:
> 
> Hello,
> When I use ISLocalToGlobalMappingGetInfo, e.g., in src/ksp/ksp/examples/tutorials/ex71.c ISLocalToGlobalMappingGetInfo(map, &nproc, &procs, &numprocs, &indices), I get the following value for nproc:
> - with 1 process: 0
> - with 2 processes: 2
> In the source code, it says that nproc is the “number of processors that are connected to this one”.
> How come this value is equal to the size of the global communicator when using 2 processes?
> According to the comment in the source code, shouldn’t the returned value be 1?
> 
> Thanks,
> Pierre