NAME

       MPI_Type_create_indexed_block -  Create an indexed datatype with constant-sized blocks

SYNOPSIS

       int MPI_Type_create_indexed_block(int count, int blocklength,
       const int array_of_displacements[],
       MPI_Datatype oldtype, MPI_Datatype *newtype)

       int MPI_Type_create_indexed_block_c(MPI_Count count, MPI_Count blocklength,
       const MPI_Count array_of_displacements[],
       MPI_Datatype oldtype,
       MPI_Datatype *newtype)

INPUT PARAMETERS

       count  - length of array of displacements (non-negative integer)
       blocklength
              - size of block (non-negative integer)
       array_of_displacements
              - array of displacements (integer)
       oldtype
              - old datatype (handle)

OUTPUT PARAMETERS

       newtype
              - new datatype (handle)

THREAD AND INTERRUPT SAFETY

       This routine is thread-safe.  This means that this routine may be safely used by multiple threads without
       the need for any user-provided thread locks.  However, the routine is  not  interrupt  safe.   Typically,
       this  is  due to the use of memory allocation routines such as malloc or other non-MPICH runtime routines
       that are themselves not interrupt-safe.

NOTES FOR FORTRAN

       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 Fortran.

NOTES

       The indices are displacements, and are based on a zero origin.  A common error is to  do  something  like
       the following
       integer a(100)
       integer blens(10), indices(10)
       do i=1,10
       10       indices(i) = 1 + (i-1)*10
       call MPI_TYPE_CREATE_INDEXED_BLOCK(10,1,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,...".   Because these are
       displacements 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)

ERRORS

       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.  Before the value is returned, the current MPI  error
       handler  is called.  By default, this error handler aborts the MPI job.  The error handler may be changed
       with   MPI_Comm_set_errhandler   (for   communicators),   MPI_File_set_errhandler   (for   files),    and
       MPI_Win_set_errhandler  (for  RMA windows).  The MPI-1 routine MPI_Errhandler_set may be used but its use
       is deprecated.  The predefined error handler MPI_ERRORS_RETURN may be used to cause error  values  to  be
       returned.   Note that MPI does not guarantee that an MPI program can continue past an error; however, MPI
       implementations will attempt to continue whenever possible.

       MPI_SUCCESS
              - No error; MPI routine completed successfully.
       MPI_ERR_ARG
              - Invalid argument.  Some argument is invalid and is not identified  by  a  specific  error  class
              (e.g., MPI_ERR_RANK ).
       MPI_ERR_COUNT
              - Invalid count argument.  Count arguments must be non-negative; a count of zero is often valid.
       MPI_ERR_TYPE
              -  Invalid  datatype  argument.  Additionally, this error can occur if an uncommitted MPI_Datatype
              (see MPI_Type_commit ) is used in a communication call.
       MPI_ERR_OTHER
              - Other error; use MPI_Error_string to get more information about this error code.

                                                    2/9/2024                    MPI_Type_create_indexed_block(3)