Parallel processing 用Fortran编写HDF5实属性

我试图在我的HDF文件中写入一个属性，如果该属性的类型为integer，那么我的代码会设法为该属性写入正确的值，但不会为reals。这是密码

! Number of processes is assumed to be 4

! PROGRAM DATASET_BY_CHUNK

  USE HDF5 ! This module contains all necessary modules 
!     USE MPI

 IMPLICIT NONE

 include 'mpif.h'

 CHARACTER(LEN=7), PARAMETER :: filename = "test.h5"  ! File name
 CHARACTER(LEN=9), PARAMETER :: dsetname = "data_test" ! Dataset name

 INTEGER(HSIZE_T), DIMENSION(1) :: data_dims

 INTEGER(HID_T) :: file_id       ! File identifier 
 INTEGER(HID_T) :: dset_id       ! Dataset identifier 
 INTEGER(HID_T) :: filespace     ! Dataspace identifier in file 
 INTEGER(HID_T) :: memspace      ! Dataspace identifier in memory
 INTEGER(HID_T) :: plist_id      ! Property list identifier
 INTEGER(HID_T) :: attr_id       ! Attribute identifier
 INTEGER(HID_T) :: aspace_id     ! Attribute Dataspace identifier
 INTEGER(HID_T) :: atype_id      ! Attribute Dataspace identifier

 INTEGER(HSIZE_T), DIMENSION(2) :: dimsf = (/4,8/) ! Dataset dimensions
 ! in the file.
 !     INTEGER, DIMENSION(7) :: dimsfi = (/4,8,0,0,0,0,0/) 
 INTEGER(HSIZE_T), DIMENSION (2) :: dimsfi = (/4,8/) 
 INTEGER(HSIZE_T), DIMENSION(2) :: chunk_dims = (/2,4/) ! Chunks dimensions

 INTEGER(HSIZE_T),  DIMENSION(2) :: count  
 INTEGER(HSSIZE_T), DIMENSION(2) :: offset 
 INTEGER(HSIZE_T),  DIMENSION(2) :: stride
 INTEGER(HSIZE_T),  DIMENSION(2) :: block



 INTEGER(HSIZE_T), DIMENSION(1) :: adims ! Attribute dimension
 INTEGER          :: arank = 1     ! Attribure rank
 INTEGER(SIZE_T)  :: attrlen     ! Length of the attribute string

 CHARACTER(LEN=80) ::  attr_data  ! Attribute data


 INTEGER, ALLOCATABLE :: data (:,:)  ! Data to write
 INTEGER :: rank = 2 ! Dataset rank

 real re

 INTEGER :: error, error_n  ! Error flags
 !
 ! MPI definitions and calls.
 !
 INTEGER :: mpierror       ! MPI error flag
 INTEGER :: comm, info
 INTEGER :: mpi_size, mpi_rank

 comm = MPI_COMM_WORLD
 info = MPI_INFO_NULL

 CALL MPI_INIT(mpierror)
 CALL MPI_COMM_SIZE(comm, mpi_size, mpierror)
 CALL MPI_COMM_RANK(comm, mpi_rank, mpierror) 
 ! Quit if mpi_size is not 4 
 if (mpi_size .NE. 4) then
    write(*,*) 'This example is set up to use only 4 processes'
    write(*,*) 'Quitting....'
    goto 100
 endif

 attr_data = "Dataset character attribute"
 !
 ! Initialize HDF5 library and Fortran interfaces.
 !
 CALL h5open_f(error) 

 ! 
 ! Setup file access property list with parallel I/O access.
 !
 CALL h5pcreate_f(H5P_FILE_ACCESS_F, plist_id, error)
 CALL h5pset_fapl_mpio_f(plist_id, comm, info, error)

 !
 ! Create the file collectively.
 ! 
 CALL h5fcreate_f(trim(filename), H5F_ACC_TRUNC_F, file_id, error, access_prp = plist_id)
 CALL h5pclose_f(plist_id, error)
 !
 ! Create some attribute
 !
 re = 20.0
 !
 ! Create scalar data space for the attribute.
 !
 call h5screate_f(H5S_SCALAR_F,aspace_id,error)
 adims=80
 !     -----------------------------
 !     Reynolds number
 CALL h5acreate_f(file_id,'Re',H5T_NATIVE_DOUBLE,aspace_id, &
      attr_id, error)
 CALL h5awrite_f(attr_id,H5T_NATIVE_DOUBLE,re,adims,error)
 CALL h5aclose_f(attr_id, error)

 !
 ! Terminate access to the data space.
 !
 CALL h5sclose_f(aspace_id, error)

 !
 ! Create the data space for the  dataset. 
 !
 CALL h5screate_simple_f(rank, dimsf, filespace, error)
 CALL h5screate_simple_f(rank, chunk_dims, memspace, error)
 !
 ! Create chunked dataset.
 !
 CALL h5pcreate_f(H5P_DATASET_CREATE_F, plist_id, error)
 CALL h5pset_chunk_f(plist_id, rank, chunk_dims, error)
 CALL h5dcreate_f(file_id, dsetname, H5T_NATIVE_INTEGER, filespace, &
                  dset_id, error, plist_id)
 CALL h5sclose_f(filespace, error)
 !
 ! Each process defines dataset in memory and writes it to the hyperslab
 ! in the file. 
 !
 stride(1) = 1 
 stride(2) = 1 
 count(1) =  1 
 count(2) =  1 
 block(1) = chunk_dims(1)
 block(2) = chunk_dims(2)
 if (mpi_rank .EQ. 0) then
     offset(1) = 0
     offset(2) = 0
 endif
 if (mpi_rank .EQ. 1) then
     offset(1) = chunk_dims(1) 
     offset(2) = 0 
 endif
 if (mpi_rank .EQ. 2) then
     offset(1) = 0 
     offset(2) = chunk_dims(2) 
 endif
 if (mpi_rank .EQ. 3) then
     offset(1) = chunk_dims(1) 
     offset(2) = chunk_dims(2) 
 endif
 ! 
 ! Select hyperslab in the file.
 !
 CALL h5dget_space_f(dset_id, filespace, error)
 CALL h5sselect_hyperslab_f (filespace, H5S_SELECT_SET_F, offset, count, error, &
                             stride, block)
 ! 
 ! Initialize data buffer with trivial data.
 !
 ALLOCATE (data(chunk_dims(1),chunk_dims(2)))
 data = mpi_rank + 1
 !
 ! Create property list for collective dataset write
 !
 CALL h5pcreate_f(H5P_DATASET_XFER_F, plist_id, error) 
 CALL h5pset_dxpl_mpio_f(plist_id, H5FD_MPIO_COLLECTIVE_F, error)

 !
 ! Write the dataset collectively. 
 !
 CALL h5dwrite_f(dset_id, H5T_NATIVE_INTEGER, data, dimsfi, error, &
                 file_space_id = filespace, mem_space_id = memspace, xfer_prp = plist_id)
 !
 ! Write the dataset independently. 
 !
 !    CALL h5dwrite_f(dset_id, H5T_NATIVE_INTEGER, data, dimsfi,error, &
 !                     file_space_id = filespace, mem_space_id = memspace)
 !
 ! Deallocate data buffer.
 !
 DEALLOCATE(data)

 !
 ! Close dataspaces.
 !
 CALL h5sclose_f(filespace, error)
 CALL h5sclose_f(memspace, error)
 !
 ! Close the dataset.
 !
 CALL h5dclose_f(dset_id, error)
 !
 ! Close the property list.
 !
 CALL h5pclose_f(plist_id, error)
 !
 ! Close the file.
 !
 CALL h5fclose_f(file_id, error)

 !
 ! Close FORTRAN interfaces and HDF5 library.
 !
 CALL h5close_f(error)

 100  continue
 CALL MPI_FINALIZE(mpierror)

 END PROGRAM DATASET_BY_CHUNK

程序运行令人满意，但当使用h5disp在Matlab中进行检查时，我得到：
属性： “Re”：0.000000

任何关于如何修复它的建议都将非常好！非常感谢

一个例子（MCVE）可以帮助你自己（发现你的错误）和我们了解你真正在做什么

这么说，这里有一个。请注意，没有错误检查，这很糟糕，糟糕，糟糕

program fa

    use hdf5

    implicit none

    character(len=8), parameter :: filename = "test.h5"

    integer(hid_t) :: file_id
    integer(hid_t) :: attr_id
    integer(hid_t) :: aspace_id
    integer(size_t), dimension(1) :: adims = (/0/)

    integer     :: ierr
    real        :: re

    re = 20.0

    call h5open_f(ierr)
    call h5fcreate_f(trim(filename), H5F_ACC_TRUNC_F, file_id, ierr)
    call h5screate_f(H5S_SCALAR_F, aspace_id, ierr)
    call h5acreate_f(file_id, 'Reynolds number', H5T_NATIVE_REAL, &
                     aspace_id, attr_id, ierr)
    call h5awrite_f(attr_id, H5T_NATIVE_REAL, re, adims, ierr)
    call h5aclose_f(attr_id, ierr)
    call h5sclose_f(aspace_id, ierr)
    call h5fclose_f(file_id, ierr)
    call h5close_f(ierr)

end program fa

如果编译、运行然后转储文件：

$ h5fc -o fa fa.f90
$ ./fa
$ h5dump test.h5
HDF5 "test.h5" {
GROUP "/" {
    ATTRIBUTE "Reynolds number" {
      DATATYPE  H5T_IEEE_F32LE
      DATASPACE  SCALAR
      DATA {
      (0): 20
      }
    }
}
}

现在我要问的关于代码的问题是为什么

adims

设置为

80

我建议三件事

MCVE

错误检查

---

关于使用MPI，您应该始终使用串行版本（在合理范围内），然后将其并行化。是的，我知道这几乎是不可能的，但如果你真的走这条路，它会让你的生活更轻松（至少从一开始）。

你希望得到什么价值？期望值从何而来？您将它保存在代码的哪一部分？Matlab代码是什么样子的？