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Diffstat (limited to 'HDF5Examples/FORTRAN/H5D/h5ex_d_nbit.F90')
| -rw-r--r-- | HDF5Examples/FORTRAN/H5D/h5ex_d_nbit.F90 | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/HDF5Examples/FORTRAN/H5D/h5ex_d_nbit.F90 b/HDF5Examples/FORTRAN/H5D/h5ex_d_nbit.F90 new file mode 100644 index 0000000..27e4d52 --- /dev/null +++ b/HDF5Examples/FORTRAN/H5D/h5ex_d_nbit.F90 @@ -0,0 +1,160 @@ +! ************************************************************ +! +! This example shows how to read and write data to a dataset +! using the N-Bit filter. The program first checks if the +! N-Bit filter is available, then if it is it writes +! integers to a dataset using N-Bit, then closes the file. +! Next, it reopens the file, reads back the data, and +! outputs the type of filter and the maximum value in the +! dataset to the screen. +! +! This file is intended for use with HDF5 Library version 1.8 +! +! ************************************************************ + +PROGRAM main + + USE HDF5 + + IMPLICIT NONE + + CHARACTER(LEN=14), PARAMETER :: filename = "h5ex_d_nbit.h5" + CHARACTER(LEN=3) , PARAMETER :: dataset = "DS1" + INTEGER , PARAMETER :: dim0 = 32 + INTEGER , PARAMETER :: dim1 = 64 + INTEGER , PARAMETER :: chunk0 = 4 + INTEGER , PARAMETER :: chunk1 = 8 + + INTEGER :: hdferr + INTEGER(HID_T) :: file, space, dset, dtype, dcpl ! Handles + INTEGER(SIZE_T) :: nelmts = 50 + INTEGER, DIMENSION(1:50) :: cd_values + INTEGER(HSIZE_T), DIMENSION(1:2) :: dims = (/dim0, dim1/), chunk = (/chunk0,chunk1/) + INTEGER(HSIZE_T), DIMENSION(1:2) :: start, stride, count, block + LOGICAL :: avail + INTEGER :: filter_id + INTEGER :: filter_info_both + INTEGER :: flags, filter_info + INTEGER, DIMENSION(1:dim0, 1:dim1) :: wdata, & ! Write buffer + rdata ! Read buffer + INTEGER :: max, i, j + INTEGER, PARAMETER :: MaxChrLen = 80 + CHARACTER(LEN=MaxChrLen) :: name + ! + ! Initialize FORTRAN interface. + ! + CALL h5open_f(hdferr) + ! Check if N-Bit compression is available and can be used for both + ! compression and decompression. Normally we do not perform error + ! checking in these examples for the sake of clarity, but in this + ! case we will make an exception because this filter is an + ! optional part of the hdf5 library. + ! + CALL h5zfilter_avail_f(H5Z_FILTER_NBIT_F, avail, hdferr) + IF (.NOT.avail) THEN + WRITE(*,'("N-Bit filter not available.",/)') + STOP 1 + ENDIF + + CALL h5zget_filter_info_f(H5Z_FILTER_NBIT_F, filter_info, hdferr) + + filter_info_both=IOR(H5Z_FILTER_ENCODE_ENABLED_F,H5Z_FILTER_DECODE_ENABLED_F) + IF (filter_info .NE. filter_info_both) THEN + WRITE(*,'("N-Bit filter not available for encoding and decoding.",/)') + STOP 1 + ENDIF + + ! Initialize data. + DO i = 1, dim0 + DO j = 1, dim1 + wdata(i,j) = (i-1)*(j-1)-(j-1) + ENDDO + ENDDO + ! + ! Create a new file using the default properties. + ! + CALL h5fcreate_f(filename, H5F_ACC_TRUNC_F, file, hdferr) + ! + ! Create dataspace. Setting size to be the current size. + ! + CALL h5screate_simple_f(2, dims, space, hdferr) + ! + ! Create the datatype to use with the N-Bit filter. It has an + ! uncompressed size of 32 bits, but will have a size of 16 bits + ! after being packed by the N-Bit filter. + ! + CALL h5tcopy_f (H5T_STD_I32LE, dtype, hdferr) + CALL h5tset_precision_f (dtype, INT(16,SIZE_T), hdferr) + CALL h5tset_offset_f (dtype, INT(5,SIZE_T), hdferr) + ! + ! Create the dataset creation property list, add the N-Bit filter + ! and set the chunk size. + ! + CALL h5pcreate_f(H5P_DATASET_CREATE_F, dcpl, hdferr) + CALL h5pset_nbit_f(dcpl, hdferr) + CALL h5pset_chunk_f(dcpl, 2, chunk, hdferr) + ! + ! Create the dataset. + ! + CALL h5dcreate_f(file, dataset, dtype, space, dset, hdferr, dcpl) + ! + ! Write the data to the dataset. + ! + CALL h5dwrite_f(dset, H5T_NATIVE_INTEGER, wdata, dims, hdferr) + ! + ! Close and release resources. + ! + CALL h5pclose_f(dcpl , hdferr) + CALL h5tclose_f(dtype, hdferr) + CALL h5dclose_f(dset , hdferr) + CALL h5sclose_f(space, hdferr) + CALL h5fclose_f(file , hdferr) + ! + ! Now we begin the read section of this example. + ! + ! Open file and dataset using the default properties. + ! + CALL h5fopen_f(filename, H5F_ACC_RDONLY_F, file, hdferr) + CALL h5dopen_f (file, dataset, dset, hdferr) + ! + ! Retrieve dataset creation property list. + ! + CALL h5dget_create_plist_f(dset, dcpl, hdferr) + ! + ! Retrieve and print the filter type. Here we only retrieve the + ! first filter because we know that we only added one filter. + ! + CALL H5Pget_filter_f(dcpl, 0, flags, nelmts, cd_values, INT(MaxChrLen, SIZE_T), name, filter_id, hdferr) + WRITE(*,'("Filter type is: ")', ADVANCE='NO') + IF(filter_id.EQ.H5Z_FILTER_DEFLATE_F)THEN + WRITE(*,'(T2,"H5Z_FILTER_DEFLATE_F")') + ELSE IF(filter_id.EQ.H5Z_FILTER_SHUFFLE_F)THEN + WRITE(*,'(T2,"H5Z_FILTER_SHUFFLE_F")') + ELSE IF(filter_id.EQ.H5Z_FILTER_FLETCHER32_F)THEN + WRITE(*,'(T2,"H5Z_FILTER_FLETCHER32_F")') + ELSE IF(filter_id.EQ.H5Z_FILTER_SZIP_F)THEN + WRITE(*,'(T2,"H5Z_FILTER_SZIP_F")') + ELSE IF(filter_id.EQ.H5Z_FILTER_NBIT_F)THEN + WRITE(*,'(T2,"H5Z_FILTER_NBIT_F")') + ENDIF + ! + ! Read the data using the default properties. + ! + CALL h5dread_f(dset, H5T_NATIVE_INTEGER, rdata, dims, hdferr) + ! + ! Find the maximum value in the dataset, to verify that it was + ! read correctly. + ! + max = MAXVAL(rdata) + ! + ! Print the maximum value. + ! + WRITE(*,'("Maximum value in ",A," is: ",i10)') dataset, max + ! + ! Close and release resources. + ! + CALL h5pclose_f(dcpl , hdferr) + CALL h5dclose_f(dset , hdferr) + CALL h5fclose_f(file , hdferr) + +END PROGRAM main |