Dear Christopher,
I guess you are producing a raw binary file, which is lacking the
structure of an unformatted fortran file. Using a fortran interface to
the MPI I/O library is not expected to change the internal file structure.
If your buffers are of equal size, you should be able to read the file
in Fortran as a binary direct file. Be aware that the unit for
expressing the size of direct access buffers is compiler-dependant.
If not, all you need is to write a few C routines for opening, making
offsets, and read buffers of specified length.
In case my analysis is correct, I attach a C template I am using for
manipulating in fortran large raw files produced either by acquisition
hardware devices or by ab-initio quantum calculations. Be aware that
this template might not be 64-bit clean. This template was contributed
by Francoise Roch at the SCCI, cf.
http://www.obs.ujf-grenoble.fr/osug/content/blogcategory/83/63/
Pierre.
Christopher G. Roberts wrote:
> Dear Sirs:
>
>
> I have successfully implemented a parallel write to file using the Fortran subroutine, MPI_FILE_WRITE() and using the MPI_FILE_SET_VIEW to displace the file pointers for each processor. The file output contains all integers and is unformmatted. The issue is that I cannot open the file in a typical Fortran program because the file does not contain the "headers" and "tails" values common to a Fortran unformatted file. The worst part is I have all my analysis codes written in F90.
>
> Is there any way I can overcome this problem or do I have to write a C function to open the data file, read it to a 1D array, pass it back to Fortran by reference, and unpack it in column major order?
>
> If you need me to send a schematic of this issue, please let me know.
>
> Thanks for your time,
>
> Chris Roberts
>
> _______________________________________________
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>
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