function h5ex_t_floatatt %************************************************************************** % % This example shows how to read and write floating point % datatypes to an attribute. The program first writes % floating ponumbers to an attribute 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 %************************************************************************** fileName = 'h5ex_t_floatatt.h5'; DATASET = 'DS1'; ATTRIBUTE = 'A1'; DIM0 = 4; DIM1 = 7; dims = [DIM0 DIM1]; wdata= zeros(dims); % % Initialize data. % for i=1: DIM0 for j=1: DIM1 ii=i-1; jj=j-1; wdata(i,j) = ii / (jj + 0.5) + jj; end end % %% Create a new file using the default properties. % file = H5F.create (fileName, 'H5F_ACC_TRUNC', 'H5P_DEFAULT', 'H5P_DEFAULT'); % % 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 (2,fliplr( dims), []); % % Create the attribute and write the floating point data to it. % In this example we will save the data as 64 bit little endian % IEEE floating point numbers, regardless of the native type. The % HDF5 library automatically converts between different floating % point types. % attr = H5A.create (dset, ATTRIBUTE, 'H5T_IEEE_F64LE', space, 'H5P_DEFAULT'); H5A.write (attr, 'H5T_NATIVE_DOUBLE', wdata); % % Close and release resources. % H5A.close (attr); H5D.close (dset); H5S.close (space); H5F.close (file); % %% Now we begin the read section of this example. Here we assume % the attribute has 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 dataspace % space = H5A.get_space (attr); [~, dims, ~] = H5S.get_simple_extent_dims (space); dims=fliplr(dims); % % Read the data. % rdata=H5A.read (attr, 'H5T_NATIVE_DOUBLE'); % % Output the data to the screen. % fprintf ('%s:\n', ATTRIBUTE); for i=1: dims(1) fprintf (' ['); for j=1: dims(2) fprintf (' %6.4f', rdata(i,j)); end fprintf (']\n'); end % % Close and release resources. % H5D.close (dset); H5S.close (space); H5F.close (file);