testdata = uint8(magic(5));
 h5create('my_example.h5','/dataset1',size(testdata)); %创建
 h5write('my_example.h5','/dataset1',testdata) %写入

h5disp('test.h5')

 testdata = h5read('test.h5','/data');
 testlabel = h5read('test.h5','/label');

  Example:  create a fixed-size 100x200 dataset.
        
       h5create('myfile.h5','/myDataset1',[100 200]);
        h5disp('myfile.h5');
 

 Example:  create a single precision 1000x2000 dataset with a chunk size
    of 50x80.  Apply the highest level of compression possible.

        h5create('myfile.h5','/myDataset2',[1000 2000], 'Datatype','single', ...
                 'ChunkSize',[50 80],'Deflate',9);
        h5disp('myfile.h5');

 Example:  create a two-dimensional dataset that is unlimited along the
    second extent.

        h5create('myfile.h5','/myDataset3',[200 Inf],'ChunkSize',[20 20]);
        h5disp('myfile.h5');