/*D
   MPI_Cart_create - Makes a new communicator to which topology information has been attached

Synopsis:
.vb
int MPI_Cart_create(MPI_Comm comm_old, int ndims, const int dims[],
                    const int periods[], int reorder, MPI_Comm *comm_cart)
.ve

Input Parameters:
+ comm_old - input communicator (handle)
. ndims - number of dimensions of Cartesian grid (integer)
. dims - integer array of size ndims specifying the number of processes in each dimension (integer)
. periods - logical array of size ndims specifying whether the grid is periodic (true) or not (false) in each dimension (logical)
- reorder - ranking may be reordered (true) or not (false)

Output Parameters:
. comm_cart - communicator with new Cartesian topology (handle)

Algorithm:
We ignore 'reorder' info currently.

.N ThreadSafe

.N Fortran

.N Errors
.N MPI_SUCCESS
.N MPI_ERR_ARG
.N MPI_ERR_COMM
.N MPI_ERR_OTHER

D*/

