%************************************************************************** % % This example shows how to read and write compound % datatypes to a dataset. The program first writes % compound structures to a dataset with a dataspace of DIM0, % 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 verion 1.6 % %************************************************************************** fileName = 'h5ex_t_cmpd.h5'; DATASET = 'DS1'; DIM0 = 4; dims = DIM0; % % Initialize data. % wdata.serial_no =int32([1153 ; 1184 ; 1027 ; 1313]); wdata.temperature =[53.23; 55.12; 130.55; 1252.89]; wdata.pressure =[24.57; 22.95; 31.23; 84.11]; % %% Create a new file using the default properties. % file = H5F.create (fileName, 'H5F_ACC_TRUNC', 'H5P_DEFAULT', 'H5P_DEFAULT'); % % Create the compound datatype for memory. % memtype = H5T.create ('H5T_COMPOUND', H5ML.sizeof (wdata)); H5T.insert (memtype, 'serial_no',H5ML.hoffset(wdata(1), 'serial_no'), 'H5T_NATIVE_INT'); H5T.insert (memtype, 'temperature',H5ML.hoffset (wdata(1), 'temperature'),'H5T_NATIVE_DOUBLE'); H5T.insert (memtype, 'pressure',H5ML.hoffset (wdata(1), 'pressure'), 'H5T_NATIVE_DOUBLE'); % % Create the compound datatype for the file. Because the standard % types we are using for the file may have different sizes than % the corresponding native types, we must manually calculate the % offset of each member. % filetype = H5T.create ('H5T_COMPOUND', 8 + 8 + 8); H5T.insert (filetype, 'serial_no', 0, 'H5T_STD_I64BE'); H5T.insert (filetype, 'temperature', 8 ,'H5T_IEEE_F64BE'); H5T.insert (filetype, 'pressure', 8 + 8,'H5T_IEEE_F64BE'); % % Create dataspace. Setting maximum size to [] sets the maximum % size to be the current size. % space = H5S.create_simple (1,fliplr( dims), []); % % Create the dataset and write the compound data to it. % dset = H5D.create (file, DATASET, filetype, space, 'H5P_DEFAULT'); H5D.write (dset, memtype, 'H5S_ALL', 'H5S_ALL', 'H5P_DEFAULT', wdata); % % Close and release resources. % H5D.close (dset); H5S.close (space); H5T.close (filetype); H5F.close (file); % %% Now we begin the read section of this example. Here we assume % the dataset has the same name and rank, but can have any size. % % % Open file and dataset. % file = H5F.open (fileName, 'H5F_ACC_RDONLY', 'H5P_DEFAULT'); dset = H5D.open (file, DATASET); % % Get dataspace and allocate memory for read buffer. % space = H5D.get_space (dset); [numdims dims maxdims] = H5S.get_simple_extent_dims (space); dims = fliplr(dims'); % % Read the data. % rdata=H5D.read (dset, memtype, 'H5S_ALL', 'H5S_ALL', 'H5P_DEFAULT'); % % Output the data to the screen. % for i=1: dims(1) fprintf ('%s[%d]:\n', DATASET, i); fprintf ('Serial number : %d\n', rdata.serial_no(i)); fprintf ('Temperature (F) : %f\n', rdata.temperature(i)); fprintf ('Pressure (inHg) : %f\n\n', rdata.pressure(i)); end % % Close and release resources. % H5D.close (dset); H5S.close (space); H5T.close (memtype); H5F.close (file);