EMD Velox: fix reading EDS stream detector lazily with `sum_EDS_detec…

…tors=True`. When summing the stream, the same stream was used several times

rsciio/emd/_emd_velox.py

@@ -950,7 +950,6 @@ def stream_to_sparse_array(self, stream_data):
         """
         # Here we load the stream data into memory, which is fine is the
         # arrays are small. We could load them lazily when lazy.
-        stream_data = self.stream_group["Data"][:].T[0]
         sparse_array = stream_readers.stream_to_sparse_COO_array(
             stream_data=stream_data,
             spatial_shape=self.reader.spatial_shape,
@@ -967,8 +966,8 @@ def stream_to_array(self, stream_data, spectrum_image=None):
 
         Parameters
         ----------
-        stream_data: array
-        spectrum_image: array or None
+        stream_data : numpy.ndarray
+        spectrum_image : numpy.ndarray or None
             If array, the data from the stream are added to the array.
             Otherwise it creates a new array and returns it.
 

rsciio/tests/test_emd_velox.py

@@ -405,6 +405,25 @@ def test_fei_si_4detectors(self, lazy, sum_EDS_detectors):
         assert len(signal) == length
         # TODO: add parsing azimuth_angle
 
+    @pytest.mark.parametrize("lazy", (False, True))
+    def test_fei_si_4detectors_compare(self, lazy):
+        fname = self.fei_files_path / "fei_SI_EDS-HAADF-4detectors_2frames.emd"
+        s_sum_EDS = hs.load(fname, sum_EDS_detectors=True, lazy=lazy)[-1]
+        s = hs.load(fname, sum_EDS_detectors=False, lazy=lazy)[-4:]
+        if lazy:
+            s_sum_EDS.compute()
+            for s_ in s:
+                s_.compute()
+
+        s2 = hs.stack(s, new_axis_name="detector").sum("detector")
+
+        np.testing.assert_allclose(s[-1].data.sum(), 865236)
+        np.testing.assert_allclose(s[-2].data.sum(), 913682)
+        np.testing.assert_allclose(s[-3].data.sum(), 867647)
+        np.testing.assert_allclose(s[-4].data.sum(), 916174)
+        np.testing.assert_allclose(s2.data.sum(), 3562739)
+        np.testing.assert_allclose(s2.data, s_sum_EDS.data)
+
     def test_fei_emd_ceta_camera(self):
         signal = hs.load(self.fei_files_path / "1532 Camera Ceta.emd")
         np.testing.assert_allclose(signal.data, np.zeros((64, 64)))