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       MPI_Type_indexed -  Creates an indexed datatype


       #include <mpi.h>
       int MPI_Type_indexed(int count, int *lengths, int *disps,
                           MPI_Datatype oldtype, MPI_Datatype *newtype)


       count  -  number  of  blocks  --  also number of entries in indices and
              - number  of  elements  in  each  block  (array  of  nonnegative
       disps  -  displacement of each block in multiples of old_type (array of
              - old datatype (handle)


              - new datatype (handle)


       The indices are displacements, and are  based  on  a  zero  origin.   A
       common error is to do something like to following

       integer a(100)
       integer blens(10), indices(10)
       do i=1,10
       blens(i)   = 1
       10       indices(i) = 1 + (i-1)*10
       call MPI_TYPE_INDEXED(10,blens,indices,MPI_INTEGER,newtype,ierr)
       call MPI_TYPE_COMMIT(newtype,ierr)
       call MPI_SEND(a,1,newtype,...)

       expecting  this to send a(1),a(11),...  because the indices have values
       1,11,...  (and so on).  Because these are disps from the beginning of a
       , it actually sends a(1+1),a(1+11),...  .

       If  you  wish  to  consider the displacements as indices into a Fortran
       array, consider declaring the Fortran array with a zero origin

       integer a(0:99)


       All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK )  have
       an  additional  argument ierr at the end of the argument list.  ierr is
       an integer and has the same meaning as the return value of the  routine
       in  C.   In Fortran, MPI routines are subroutines, and are invoked with
       the call statement.

       All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in


       If an error occurs in an MPI function, the current MPI error handler is
       called to handle it.  By default, this error  handler  aborts  the  MPI
       job.   The  error  handler may be changed with MPI_Errhandler_set ; the
       predefined error handler MPI_ERRORS_RETURN may be used to  cause  error
       values  to  be  returned  (in C and Fortran; this error handler is less
       useful in with the C++ MPI  bindings.   The  predefined  error  handler
       MPI::ERRORS_THROW_EXCEPTIONS  should  be used in C++ if the error value
       needs to be recovered).  Note that MPI does not guarantee that  an  MPI
       program can continue past an error.

       All  MPI  routines  (except  MPI_Wtime  and MPI_Wtick ) return an error
       value; C routines as the value of the function and Fortran routines  in
       the  last  argument.   The  C++  bindings  for  MPI do not return error
       values; instead, error values are communicated by  throwing  exceptions
       of  type  MPI::Exception  (but  not  by  default).  Exceptions are only
       thrown if the error value is not MPI::SUCCESS .

       Note that if the MPI::ERRORS_RETURN handler is set in  C++,  while  MPI
       functions  will  return  upon an error, there will be no way to recover
       what the actual error value was.
              - Invalid count argument.  Count arguments must be non-negative;
              a count of zero is often valid.
              - Invalid datatype argument.  May be an uncommitted MPI_Datatype
              (see MPI_Type_commit ).
              - Invalid count argument.  Count arguments must be non-negative;
              a count of zero is often valid.
              -  Invalid  argument.   Some  argument  is  invalid  and  is not
              identified by a specific error class.  This is typically a  NULL
              pointer or other such error.
              -  This  error  is  returned  when  some  part  of  the  LAM/MPI
              implementation is unable to acquire memory.


       For more information, please see the official MPI Forum web site, which
       contains  the  text  of  both  the  MPI-1  and  MPI-2 standards.  These
       documents contain detailed information about each MPI function (most of
       which is not duplicated in these man pages).


       The  LAM Team would like the thank the MPICH Team for the handy program
       to       generate        man        pages        ("doctext"        from     ),    the    initial
       formatting, and some initial text for most of the MPI-1 man pages.