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)

INPUT PARAMETERS

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

OUTPUT PARAMETERS

       newtype
              - new datatype (handle)

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)

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.

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 guarentee 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_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_ARG
              - Invalid argument.  Some argument is invalid and is not identified by  a  specific
              error class (e.g., MPI_ERR_RANK ).

                                            11/12/2016           MPI_Type_create_indexed_block(3)