On Nov 10, 2015, at 9:45 AM, victor sv <victo...@gmail.com<mailto:victo...@gmail.com>> wrote:
Thank you Scott for the quick response. It seems that the Fortran2003 interface for H5Dwrite solves both questions, but there are other subroutines like H5Screate_simple_f or H5Sselect_hyperslab_f using HSIZE_T integers to specify dimensions or offsets. I still have the following doubts: * HSIZE_T can be an integer of different kinds depending on the platform? Correct, the size of hsize_t can be dependent on the platform. * What is the easiest way to handle dataspaces with offsets or dimensions bigger than HSIZE_T? Keep in mind that the size of hsize_t is the same size as that found in C, that is by design. But I’m assuming that the issue you are referring to is that hsize_t in C is an unsigned integer and Fortran does not have unsigned integers. So, for example, if C’s hsize_t is of type long (8 bytes) the largest number will be 18,446,744,073,709,551,615. But in fortran, for an 8 byte integer, the largest number will be 9,223,372,036,854,775,807 because it is signed. So it is possible that if an HDF5 file was written in C and the number exceeds 9,223,372,036,854,775,807 (for example) then the fortran code will not be able to read the file. Scot Best regards, Víctor. 2015-11-10 15:53 GMT+01:00 Scot Breitenfeld <brtn...@hdfgroup.org<mailto:brtn...@hdfgroup.org>>: I would suggest you use the Fortran 2003 interface for h5dwrite_f instead: SUBROUTINE h5dwrite_f(dset_id, mem_type_id, buf, hdferr, & mem_space_id, file_space_id, xfer_prp) INTEGER(HID_T), INTENT(IN) :: dset_id INTEGER(HID_T), INTENT(IN) :: mem_type_id TYPE(C_PTR) , INTENT(IN) :: buf INTEGER , INTENT(OUT) :: hdferr INTEGER(HID_T), INTENT(IN) , OPTIONAL :: mem_space_id INTEGER(HID_T), INTENT(IN) , OPTIONAL :: file_space_id INTEGER(HID_T), INTENT(IN) , OPTIONAL :: xfer_prp as you don’t have to worry about passing the dimensions of the array to the API. You can also use ‘h5kind_to_type' to pass the appropriate type, for example ! ! Find the HDF type corresponding to the specified KIND ! h5_kind_type_i = h5kind_to_type(ip,H5_INTEGER_KIND) Take a look at h5ex_d_rdwr_kind_F03.f90 for an example of how to handle different kinds of integers and reals, https://www.hdfgroup.org/HDF5/examples/api18-fortran.html Scot > On Nov 10, 2015, at 2:17 AM, victor sv > <victo...@gmail.com<mailto:victo...@gmail.com>> wrote: > > Hi all, > > I'm trying to implement a layer to export the data of our application to XDMF > format on top of HDF5. The data > types that we want to handle are integers and reals of both single and double > precision. > > I would like to know the actual state of the HDF5 Fortran interface for > handling double precision integers. > > In particular, if we observe to the interface of the H5DWrite_f subroutine > below (and its comments) we can see that the > data type of the buffer (buf) could be INTEGER, and the data type of the > dimensions is HSIZE_T. > > SUBROUTINE h5dwrite_vl_f(dset_id, mem_type_id, buf, dims > , len, hdferr, & > mem_space_id, file_space_id, xfer_prp) > IMPLICIT NONE > ... > > INTEGER(HID_T), INTENT(IN) :: mem_type_id ! Memory datatype identifier > TYPE, INTENT(IN), & DIMENSION(dims(1),dims(2)) :: buf > ! Data buffer; may be a scalar > ! or an array > ! TYPE must be one of the > following > ! INTEGER > ! REAL > ! CHARACTER > INTEGER(HSIZE_T), INTENT(IN), DIMENSION(2) :: dims > ! Array to hold corresponding > ! dimension sizes of data > ! buffer buf > ! dim(k) has value of the k-th > ! dimension of buffer buf > ! Values are ignored if buf is > ! a scalar > > ... > > I've read that the HSIZE_T data type depends on the architecture and it's > defined at HDF5 compilation time and I can check > that in my own compilation it's as double precision integer (64 bits). Is > there any case where this value is a single precision > integer (32)? In any case, how can I handle the writing of datasets bigger > than max(HSIZE_T)? > > A different questions are about the data type of the raw data. In my HDF5 > compilation it seems that the H5DWrite_f procedure > doesn't compile if the buf actual argument is a double precision integer. > There is a native Fortran HDF5 mem_type_id for > double precision integers? > > In some forum I've also read that the H5T_NATIVE_INTEGER could be a doble > precision integer. If this is true, it is posible to > handle single precision and double precision integers in the same > application/software? > > Thanks in advance, > Víctor. > > > > _______________________________________________ > Hdf-forum is for HDF software users discussion. > Hdf-forum@lists.hdfgroup.org<mailto:Hdf-forum@lists.hdfgroup.org> > http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org > Twitter: https://twitter.com/hdf5 _______________________________________________ Hdf-forum is for HDF software users discussion. Hdf-forum@lists.hdfgroup.org<mailto:Hdf-forum@lists.hdfgroup.org> http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org Twitter: https://twitter.com/hdf5 _______________________________________________ Hdf-forum is for HDF software users discussion. Hdf-forum@lists.hdfgroup.org<mailto:Hdf-forum@lists.hdfgroup.org> http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org Twitter: https://twitter.com/hdf5
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