[MPICH] MPI-IO and Create_indexed datatype

[Russell L. Carter]

Hi,
I want to use collective Read_all and Write_all to a
multi-zone structured file which has a header for each
zone in which all of the fields save exactly one are
homogeneous floating point types.  The one field is an int.
Each zone may have arbitrary dimensions but is otherwise
consistently structured.  (This is an OVERFLOW Q file)

Reading in Section 3.4.5 of "Using MPI-2" I got the
idea that possibly Datatype::Create_indexed might be
applicable, but it seems from what I can infer from the
various documentation sources that the displacements
vector is populated with extents, not byte offsets.  Thus
apparently Create_indexed won't work because of that
single int field, which precludes using extents.  Do
I understand the situation correctly?  Is there a
best practices approach for implementing higher level
operations with this sort of data layout?

Thanks very much,
Russell


-- 
Russell L. Carter
Esturion, LLC
2285 Sandia Drive
Prescott, Arizona 86301

rcarter at esturion.net
928 308-4154