put rotation angle and image key in processed data group

mantidimaging/core/io/saver.py

@@ -223,8 +223,6 @@ def _nexus_save(nexus_file: h5py.File, dataset: StrictDataset, sample_name: str)
     _set_nx_class(detector, "NXdetector")
     detector.create_dataset("image_key", data=dataset.image_keys)
 
-    _save_processed_data_to_nexus(nexus_file, dataset)
-
     # sample field
     sample_group = tomo_entry.create_group("sample")
     _set_nx_class(sample_group, "NXsample")
@@ -234,6 +232,8 @@ def _nexus_save(nexus_file: h5py.File, dataset: StrictDataset, sample_name: str)
     rotation_angle = sample_group.create_dataset("rotation_angle", data=np.concatenate(dataset.nexus_rotation_angles))
     rotation_angle.attrs["units"] = "rad"
 
+    _save_processed_data_to_nexus(nexus_file, dataset, rotation_angle, detector["image_key"])
+
     # data field
     data = tomo_entry.create_group("data")
     _set_nx_class(data, "NXdata")
@@ -245,8 +245,11 @@ def _nexus_save(nexus_file: h5py.File, dataset: StrictDataset, sample_name: str)
         _save_recon_to_nexus(nexus_file, recon, dataset.sample.filenames[0])
 
 
-def _save_processed_data_to_nexus(nexus_file: h5py.File, dataset: StrictDataset):
+def _save_processed_data_to_nexus(nexus_file: h5py.File, dataset: StrictDataset, rotation_angle: h5py.Group,
+                                  image_key: h5py.Dataset):
     data = nexus_file.create_group("processed-data")
+    data["rotation_angle"] = rotation_angle
+    data["image_key"] = image_key
     _set_nx_class(data, "NXdata")
     combined_data_shape = (sum([len(arr) for arr in dataset.nexus_arrays]), ) + dataset.nexus_arrays[0].shape[1:]
     data.create_dataset("data", shape=combined_data_shape, dtype="float32")

mantidimaging/core/io/test/io_test.py

@@ -263,8 +263,7 @@ def test_nexus_missing_projection_angles_save_as_zeros(self):
             # test rotation angle links
             self.assertEqual(tomo_entry["data"]["rotation_angle"], rotation_angle_entry)
 
-    @staticmethod
-    def test_nexus_complex_dataset_save():
+    def test_nexus_complex_dataset_save(self):
         image_stacks = []
         for _ in range(5):
             image_stack = th.generate_images()
@@ -278,12 +277,12 @@ def test_nexus_complex_dataset_save():
             saver._nexus_save(nexus_file, sd, "sample-name")
             tomo_entry = nexus_file["entry1"]["tomo_entry"]
 
-            # test instrument field
             npt.assert_array_equal(
                 np.array(nexus_file["processed-data"]["data"]),
                 np.concatenate(
                     [sd.dark_before.data, sd.flat_before.data, sd.sample.data, sd.flat_after.data,
                      sd.dark_after.data]).astype("float32"))
+            # test instrument field
             npt.assert_array_equal(
                 np.array(tomo_entry["instrument"]["detector"]["image_key"]),
                 [2 for _ in range(sd.dark_before.data.shape[0])] + [1 for _ in range(sd.flat_before.data.shape[0])] +
@@ -293,6 +292,9 @@ def test_nexus_complex_dataset_save():
             # test instrument/sample fields
             npt.assert_array_equal(np.array(tomo_entry["sample"]["rotation_angle"]),
                                    np.concatenate([images.projection_angles().value for images in image_stacks]))
+            self.assertEqual(nexus_file["processed-data"]["rotation_angle"], tomo_entry["sample"]["rotation_angle"])
+            self.assertEqual(nexus_file["processed-data"]["image_key"],
+                             tomo_entry["instrument"]["detector"]["image_key"])
 
     @mock.patch("mantidimaging.core.io.saver.h5py.File")
     @mock.patch("mantidimaging.core.io.saver._nexus_save")