smilei reader: add the possibility to process real fields (#287)

Add the possibility to process real fields

The field of the laser envelope is real without imaginary part, therefore the structure of the hdf5 file is slightly different. With this small adjustment of getExpanded it is now possible to also process the real fields of Laser Envelope.

postpic/datareader/smileih5.py

@@ -216,9 +216,14 @@ def _getExpanded(self, key, theta=0):
 
             field_name = key+"_mode_"+str(mode)
             field_array = np.array(self._data[field_name])
-            field_array_shape = field_array.shape
-            reshaped_array = field_array.reshape(field_array_shape[0], field_array_shape[1]//2, 2)
-            complex_array = reshaped_array[:, :, 0] + 1j * reshaped_array[:, :, 1]
+            # The Envelope Fields are real without imaginary part.
+            if key.startswith('Env_'):
+                complex_array = field_array
+            else:
+                field_array_shape = field_array.shape
+                reshaped_array = field_array.reshape(field_array_shape[0],
+                                                     field_array_shape[1]//2, 2)
+                complex_array = reshaped_array[:, :, 0] + 1j * reshaped_array[:, :, 1]
             array_list.append(complex_array)
 
         # Modified array of shape (Nmodes, Nx, Nr)