!************************************************************ ! ! This example shows how to read and write bitfield ! datatypes to a dataset. The program first writes bit ! fields to a dataset with a dataspace of DIM0xDIM1, then ! closes the file. Next, it reopens the file, reads back ! the data, and outputs it to the screen. ! ! This file is intended for use with HDF5 Library version 1.8 ! with --enable-fortran2003 ! !************************************************************ PROGRAM main USE HDF5 USE ISO_C_BINDING IMPLICIT NONE CHARACTER(LEN=20), PARAMETER :: filename = "h5ex_t_bit_F03.h5" CHARACTER(LEN=3) , PARAMETER :: dataset = "DS1" INTEGER , PARAMETER :: dim0 = 4 INTEGER , PARAMETER :: dim1 = 7 INTEGER(HID_T) :: file, space, dset ! Handles INTEGER :: hdferr INTEGER(HSIZE_T), DIMENSION(1:2) :: dims = (/dim0, dim1/) INTEGER(HSIZE_T), DIMENSION(1:2) :: maxdims INTEGER(C_SIGNED_CHAR), DIMENSION(1:dim0, 1:dim1), TARGET :: wdata ! Write buffer INTEGER(C_SIGNED_CHAR), DIMENSION(:,:), ALLOCATABLE, TARGET :: rdata ! Read buffer INTEGER :: A, B, C, D INTEGER :: i, j INTEGER, PARAMETER :: hex = Z'00000003' TYPE(C_PTR) :: f_ptr ! ! Initialize FORTRAN interface. ! CALL h5open_f(hdferr) ! ! Initialize data. We will manually pack 4 2-bit integers into ! each unsigned char data element. ! DO i = 0, dim0-1 DO j = 0, dim1-1 wdata(i+1,j+1) = 0 wdata(i+1,j+1) = IOR( wdata(i+1,j+1), IAND(i * j - j, hex)) ! Field "A" wdata(i+1,j+1) = IOR( wdata(i+1,j+1), ISHFT(IAND(i,hex),2)) ! Field "B" wdata(i+1,j+1) = IOR( wdata(i+1,j+1), ISHFT(IAND(j,hex),4)) ! Field "C" wdata(i+1,j+1) = IOR( wdata(i+1,j+1), ISHFT(IAND(i+j,hex),6)) ! Field "D" ENDDO ENDDO ! ! Create a new file using the default properties. ! CALL h5fcreate_f(filename, H5F_ACC_TRUNC_F, file, hdferr) ! ! Create dataspace. Setting maximum size to be the current size. ! CALL h5screate_simple_f(2, dims, space, hdferr) ! ! Create the dataset and write the bitfield data to it. ! CALL H5Dcreate_f(file, dataset, H5T_STD_B8BE, space, dset, hdferr) f_ptr = C_LOC(wdata(1,1)) CALL H5Dwrite_f(dset, H5T_NATIVE_B8, f_ptr, hdferr) ! ! Close and release resources. ! 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, dataset. ! CALL h5fopen_f(filename, H5F_ACC_RDONLY_F, file, hdferr) CALL h5dopen_f(file, dataset, dset, hdferr) ! ! Get dataspace and allocate memory for read buffer. ! CALL H5Dget_space_f(dset, space, hdferr) CALL H5Sget_simple_extent_dims_f(space, dims, maxdims, hdferr) ALLOCATE(rdata(1:dims(1),1:dims(2))) ! ! Read the data. ! f_ptr = C_LOC(rdata) CALL H5Dread_f(dset, H5T_NATIVE_B8, f_ptr, hdferr) ! ! Output the data to the screen. ! WRITE(*,'(A,":")') dataset DO i = 1, dims(1) WRITE(*,'(" [ ")', ADVANCE='NO') DO j = 1, dims(2) A = IAND(rdata(i,j), hex) ! Retrieve field "A" B = IAND(ISHFT(rdata(i,j),-2), hex) ! Retrieve field "B" C = IAND(ISHFT(rdata(i,j),-4), hex) ! Retrieve field "C" D = IAND(ISHFT(rdata(i,j),-6), hex) ! Retrieve field "D" WRITE(*,'(A1,4I2,A2)', ADVANCE='NO') "{",A, B, C, D,"} " ENDDO WRITE(*,'(A1)') "]" ENDDO ! ! Close and release resources. ! DEALLOCATE(rdata) CALL H5Dclose_f(dset, hdferr) CALL H5Sclose_f(space, hdferr) CALL H5Fclose_f(file, hdferr) END PROGRAM main