%************************************************************************** % % This example shows how to read and write string datatypes % to a dataset. The program first writes strings 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_string.h5'; DATASET = 'DS1'; DIM0 = 4; SDIM = 8; dims = DIM0; wdata = ['Parting'; 'is such'; 'sweet '; 'sorrow.']; % % Create a new file using the default properties. % file = H5F.create (fileName, 'H5F_ACC_TRUNC', 'H5P_DEFAULT', 'H5P_DEFAULT'); % % Create file and memory datatypes. MATLAB strings do not have \0's. % filetype = H5T.copy ('H5T_FORTRAN_S1'); H5T.set_size (filetype, SDIM - 1); memtype = H5T.copy ('H5T_C_S1'); H5T.set_size (memtype, SDIM - 1); % % 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 string data to it. % dset = H5D.create (file, DATASET, filetype, space, 'H5P_DEFAULT'); % Transpose the data to match the layout in the H5 file to match C % generated H5 file. H5D.write (dset, memtype, 'H5S_ALL', 'H5S_ALL', 'H5P_DEFAULT', wdata'); % % Close and release resources. % H5D.close (dset); H5S.close (space); H5T.close (filetype); H5T.close (memtype); H5F.close (file); % %% Now we begin the read section of this example. Here we assume % the dataset and string have 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 the datatype and its size. % filetype = H5D.get_type (dset); sdim = H5T.get_size (filetype); sdim = sdim+1; % Make room for null terminator % % % Get dataspace % space = H5D.get_space (dset); [numdims dims maxdims] = H5S.get_simple_extent_dims (space); dims=fliplr(dims'); % % Create the memory datatype. % memtype = H5T.copy ('H5T_C_S1'); H5T.set_size (memtype, sdim); % % 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]: %s\n', DATASET, i, char(rdata(:,i))); end % % Close and release resources. % H5D.close (dset); H5S.close (space); H5T.close (filetype); H5T.close (memtype); H5F.close (file);