function h5ex_t_stringatt %************************************************************************** % % This example shows how to read and write string datatypes % to an attribute. The program first writes strings to an % attribute 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 version 1.8 %************************************************************************** fileName = 'h5ex_t_stringatt.h5'; DATASET = 'DS1'; ATTRIBUTE = 'A1'; 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 dataset with a scalar dataspace. % space = H5S.create ('H5S_SCALAR'); dset = H5D.create (file, DATASET, 'H5T_STD_I32LE', space, 'H5P_DEFAULT'); H5S.close (space); % % Create dataspace. Setting maximum size to [] sets the maximum % size to be the current size. % space = H5S.create_simple (1,fliplr( dims), []); % % Create the attribute and write the string data to it. % attr = H5A.create (dset, ATTRIBUTE, filetype, space, 'H5P_DEFAULT'); H5A.write (attr, memtype, wdata'); % % Close and release resources. % H5A.close (attr); 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 attribute and string have the same name and rank, but can % have any size. % % % Open file, dataset, and attribute. % file = H5F.open (fileName, 'H5F_ACC_RDONLY', 'H5P_DEFAULT'); dset = H5D.open (file, DATASET); attr = H5A.open_name (dset, ATTRIBUTE); % % Get the datatype and its size. % filetype = H5A.get_type (attr); sdim = H5T.get_size (filetype); sdim = sdim + 1; % Make room for null terminator % % % Get dataspace % space = H5A.get_space (attr); [~, dims, ~] = 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=H5A.read (attr, memtype); % % Output the data to the screen. % for i=1: dims(1) fprintf ('%s[%d]: %s\n', ATTRIBUTE, i, char(rdata(:,i))); end % % Close and release resources. % H5A.close (attr); H5D.close (dset); H5S.close (space); H5T.close (filetype); H5T.close (memtype); H5F.close (file);