MPITypevector(3OpenMPI) MPITypevector(3OpenMPI)

NAME
       MMPPIITTyyppeevveeccttoorr - Creates a vector (strided) datatype.


SSYYNNTTAAXX
CC SSyynnttaaxx
       #include 
       int MPITypevector(int count, int blocklength, int stride,
            MPIDatatype oldtype, MPIDatatype *newtype)


FFoorrttrraann SSyynnttaaxx
       INCLUDE 'mpif.h'
       MPITYPEVECTOR(COUNT, BLOCKLENGTH, STRIDE, OLDTYPE, NEWTYPE,
                 IERROR)
            INTEGER   COUNT, BLOCKLENGTH, STRIDE, OLDTYPE
            INTEGER   NEWTYPE, IERROR


CC++++ SSyynnttaaxx
       #include 
       Datatype Datatype::Createvector(int count, int blocklength,
            int stride) const


IINNPPUUTT PPAARRAAMMEETTEERRSS
       count     Number of blocks (nonnegative integer).

       blocklength
                 Number of elements in each block (nonnegative integer).

       stride    Number of elements between start of each block (integer).

       oldtype   Old datatype (handle).



OOUUTTPPUUTT PPAARRAAMMEETTEERRSS
       newtype   New datatype (handle).


       IERROR    Fortran only: Error status (integer).


DESCRIPTION
       The  function  MPITypevector  is  a  general  constructor that allows
       replication of a datatype into locations that consist of equally spaced
       blocks.  Each  block  is  obtained  by concatenating the same number of
       copies of the old datatype. The spacing between blocks is a multiple of
       the extent of the old datatype.

       EExxaammppllee  11::  Assume,  again,  that  oldtype  has type map {(double, 0),
       (char, 8)}, with extent 16. A call to  MPITypevector(2,  3,  4,  old-
       type, newtype) will create the datatype with type map
           {(double, 0), (char, 8), (double, 16), (char, 24),
           (double, 32), (char, 40),
           (double, 64), (char, 72),
           (double, 80), (char, 88), (double, 96), (char, 104)}

       That  is,  two  blocks  with  three copies each of the old type, with a
       stride of 4 elements (4 x 6 bytes) between the blocks.

       EExxaammppllee 22::  A call to  MPITypevector(3, 1, -2, oldtype, newtype) will
       create the datatype

           {(double, 0), (char, 8), (double, -32), (char, -24),
           (double, -64), (char, -56)}

       In general, assume that oldtype has type map

           {(type(0), disp(0)), ..., (type(n-1), disp(n-1))},

       with  extent  ex. Let bl be the blocklength. The newly created datatype
       has a type map with count x bl x  n entries:

           {(type(0), disp(0)), ..., (type(n-1), disp(n-1)),
           (type(0), disp(0) + ex), ..., (type(n-1), disp(n-1) + ex), ...,
           (type(0), disp(0) + (bl -1) * ex),...,
           (type(n-1), disp(n-1) + (bl -1)* ex),
           (type(0), disp(0) + stride * ex),..., (type(n-1),
           disp(n-1) + stride * ex), ...,
           (type(0), disp(0) + (stride + bl - 1) * ex), ...,
           (type(n-1), disp(n-1) + (stride + bl -1) * ex), ...,
           (type(0), disp(0) + stride * (count -1) * ex), ...,
           (type(n-1), disp(n-1) + stride * (count -1) * ex), ...,
           (type(0), disp(0) + (stride * (count -1) + bl -1) * ex), ...,
           (type(n-1), disp(n-1) + (stride * (count -1) + bl -1) * ex)}

       A call to MPITypecontiguous(count, oldtype, newtype) is equivalent to
       a  call to MPITypevector(count, 1, 1, oldtype, newtype), or to a call
       to MPITypevector(1, count, n, oldtype, newtype), n arbitrary.


EERRRROORRSS
       Almost all MPI routines return an error value; C routines as the  value
       of  the  function  and Fortran routines in the last argument. C++ func-
       tions do not return errors. If the default  error  handler  is  set  to
       MPI::ERRORSTHROWEXCEPTIONS, then on error the C++ exception mechanism
       will be used to throw an MPI:Exception object.

       Before the error value is returned, the current MPI  error  handler  is
       called.  By  default, this error handler aborts the MPI job, except for
       I/O  function  errors.  The  error  handler   may   be   changed   with
       MPICommseterrhandler; the predefined error handler MPIERRORSRETURN
       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.


SEE ALSO
       MPITypecreatehvector
       MPITypehvector




Open MPI 1.2                    September 2006       MPITypevector(3OpenMPI)