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<H1 id="MPI_Type_hindexed">MPI_Type_hindexed</H1>
Creates an indexed datatype with offsets in bytes
<H2>Synopsis</H2>
<PRE>
int MPI_Type_hindexed(int count,
int *array_of_blocklengths,
MPI_Aint * array_of_displacements,
MPI_Datatype oldtype, MPI_Datatype * newtype)
</PRE>
<H2>Input Parameters</H2>
<DL>
<DT><B>count </B> <DD> number of blocks -- also number of entries in array_of_displacements and array_of_blocklengths
<DT><B>array_of_blocklengths </B> <DD> number of elements in each block (array of nonnegative integers)
<DT><B>array_of_displacements </B> <DD> byte displacement of each block (array of MPI_Aint)
<DT><B>oldtype </B> <DD> old datatype (handle)
</DL>
<P>
<H2>Output Parameters</H2>
<DL>
<DT><B>newtype </B> <DD> new datatype (handle)
</DL>
<P>
<H2>Deprecated Function</H2>
The MPI-2 standard deprecated a number of routines because MPI-2 provides
better versions. This routine is one of those that was deprecated. The
routine may continue to be used, but new code should use the replacement
routine.
This routine is replaced by <tt>MPI_Type_create_hindexed</tt>.
<P>
<H2>Thread and Interrupt Safety</H2>
<P>
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 <tt>malloc
</tt>or other non-MPICH runtime routines that are themselves not interrupt-safe.
<P>
<H2>Notes for Fortran</H2>
All MPI routines in Fortran (except for <tt>MPI_WTIME</tt> and <tt>MPI_WTICK</tt>) have
an additional argument <tt>ierr</tt> at the end of the argument list. <tt>ierr
</tt>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
<tt>call</tt> statement.
<P>
All MPI objects (e.g., <tt>MPI_Datatype</tt>, <tt>MPI_Comm</tt>) are of type <tt>INTEGER
</tt>in Fortran.
<P>
The array_of_displacements are displacements, and are based on a zero origin. A common error
is to do something like to following
<PRE>
integer a(100)
integer array_of_blocklengths(10), array_of_displacements(10)
do i=1,10
array_of_blocklengths(i) = 1
10 array_of_displacements(i) = (1 + (i-1)*10) * sizeofint
call MPI_TYPE_HINDEXED(10,array_of_blocklengths,array_of_displacements,MPI_INTEGER,newtype,ierr)
call MPI_TYPE_COMMIT(newtype,ierr)
call MPI_SEND(a,1,newtype,...)
</PRE>
expecting this to send "a(1),a(11),..." because the array_of_displacements have values
"1,11,...". Because these are <em>displacements</em> from the beginning of "a",
it actually sends "a(1+1),a(1+11),...".
<P>
If you wish to consider the displacements as array_of_displacements into a Fortran array,
consider declaring the Fortran array with a zero origin
<PRE>
integer a(0:99)
</PRE>
<P>
<H2>Errors</H2>
<P>
All MPI routines (except <tt>MPI_Wtime</tt> and <tt>MPI_Wtick</tt>) 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 <tt>MPI_Comm_set_errhandler</tt> (for communicators),
<tt>MPI_File_set_errhandler</tt> (for files), and <tt>MPI_Win_set_errhandler</tt> (for
RMA windows). The MPI-1 routine <tt>MPI_Errhandler_set</tt> may be used but
its use is deprecated. The predefined error handler
<tt>MPI_ERRORS_RETURN</tt> may be used to cause error values to be returned.
Note that MPI does <em>not</em> guarentee that an MPI program can continue past
an error; however, MPI implementations will attempt to continue whenever
possible.
<P>
<DL>
<DT><B>MPI_SUCCESS </B> <DD> No error; MPI routine completed successfully.
</DL>
<DL>
<DT><B>MPI_ERR_TYPE </B> <DD> Invalid datatype argument. Additionally, this error can
occur if an uncommitted MPI_Datatype (see <tt>MPI_Type_commit</tt>) is used
in a communication call.
</DL>
<DL>
<DT><B>MPI_ERR_COUNT </B> <DD> Invalid count argument. Count arguments must be
non-negative; a count of zero is often valid.
</DL>
<DL>
<DT><B>MPI_ERR_INTERN </B> <DD> This error is returned when some part of the MPICH
implementation is unable to acquire memory.
</DL>
<DL>
<DT><B>MPI_ERR_ARG </B> <DD> Invalid argument. Some argument is invalid and is not
identified by a specific error class (e.g., <tt>MPI_ERR_RANK</tt>).
</DL>
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