94 lines
2.6 KiB
Fortran
94 lines
2.6 KiB
Fortran
!
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! Copyright (c) 2006-2015, The Regents of the University of California,
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! through Lawrence Berkeley National Laboratory (subject to receipt of any
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! required approvals from the U.S. Dept. of Energy) and the Paul Scherrer
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! Institut (Switzerland). All rights reserved.!
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!
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! License: see file COPYING in top level of source distribution.
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!
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include 'H5hut.f90'
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program read_setviewf
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use H5hut
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implicit none
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#if defined(PARALLEL_IO)
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include 'mpif.h'
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#endif
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! name of input file
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character (len=*), parameter :: fname = "example_setview.h5"
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! H5hut verbosity level
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integer*8, parameter :: h5_verbosity = H5_VERBOSE_DEFAULT
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integer :: comm_size = 1
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integer :: comm_rank = 0
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integer*8 :: file, h5_ierror
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integer*8 :: num_particles, num_particles_total
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integer*8 :: i, start, end, remainder
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integer*4, allocatable :: data(:)
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! initialize MPI & H5hut
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#if defined(PARALLEL_IO)
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integer :: comm, mpi_ierror
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comm = MPI_COMM_WORLD
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call mpi_init (mpi_ierror)
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call mpi_comm_size (comm, comm_size, mpi_ierror)
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call mpi_comm_rank (comm, comm_rank, mpi_ierror)
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#endif
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call h5_abort_on_error ()
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call h5_set_verbosity_level (h5_verbosity)
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! open file and go to first step
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file = h5_openfile (fname, H5_O_RDONLY, H5_PROP_DEFAULT)
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h5_ierror = h5_setstep(file, 1_8)
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! compute a "canonical" view:
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! all cores get almost the same number of particles
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num_particles_total = h5pt_getnpoints (file);
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num_particles = num_particles_total / comm_size;
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remainder = mod (num_particles_total, comm_size);
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start = comm_rank * num_particles;
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! adjust number of local particles
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if (comm_rank < remainder) then
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num_particles = num_particles + 1
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end if
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! adjust start
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if (comm_rank < remainder) then
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start = start + comm_rank
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else
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start = start + remainder
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end if
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! Note:
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! setting end = start - 1 forces the selection of zero particles!
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end = start + num_particles - 1;
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! adjust Fortran indices: in Fortran we start at 1 not 0
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start = start + 1
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end = end + 1
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write (*, "('[proc ', i4, ']: set view to [', i4, '..', i4, ']')") comm_rank, start, end
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h5_ierror = h5pt_setview (file, start, end);
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! read and print data
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allocate (data (num_particles))
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h5_ierror = h5pt_readdata_i4 (file, "data", data);
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do i = 1, num_particles
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write (*, "('[proc ', i4, ']: global index = ', i4, '; local index = ', i4, ', value = ', i4)") &
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comm_rank, start+i-1, i, data(i)
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end do
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! cleanup
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deallocate (data)
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h5_ierror = h5_closefile (file)
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#if defined(PARALLEL_IO)
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call mpi_finalize (mpi_ierror)
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#endif
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end program read_setviewf
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