title: h5 KeyError: "Unable to open object (object 'data' doesn't exist)"
body: <p>I am taking a previously generated .h5 file which is 3D and taking a 2D slice. The new 2D h5 file looks complete and as expected, however I then pass this into some modeling software (GPRMax) and get the error KeyError: &quot;Unable to open object (object 'data' doesn't exist)&quot;. Previous 2D and 3D .h5 files have been fine, so im not sure whats different. Below is the code used to generate the .h5 file. Any help is appreciated.</p>
  <pre><code>hf = h5py.File(dir_path+'\ModelMC0105\ModelA3d1_15102020_170900005701.h5', 'r')
  
  dset = hf['data']
  
  if os.path.exists(dir_path+'\ModelMC0105\ModelA3d1_15102020_170900005701-slice.h5'):
      os.remove(dir_path+'\ModelMC0105\ModelA3d1_15102020_170900005701-slice.h5')
  
  hf2 = h5py.File(dir_path+'\ModelMC0105\ModelA3d1_15102020_170900005701-slice.h5','w')
  
  
  dz_dy_dz = (0.001,0.001,0.001)
  hf2.attrs['dx_dy_dz'] = dz_dy_dz
  
  data = hf2.create_dataset(&quot;data&quot;, (100,1,100))
  
  for i in range(100):
      data[i]=(dset[i,50,:])
  
  data=data.ref
  print(data)
  
  hf2.close()
  hf.close()
  </code></pre>