[ESSSPECTROSCOPY] Make BFIROST detector_number contiguous

packages/essspectroscopy/src/ess/bifrost/data.py

@@ -11,13 +11,13 @@
     'ess/bifrost',
     files={
         "bifrost_260526T151446.repack.h5": "md5:0f60f5938b0dce87542dd525a2f9a5c4",
-        "computed_energy_data_simulated_5x2.h5": "md5:6fee639c3c05523dfa18262cf2b03958",
+        "computed_energy_data_simulated_5x2.h5": "md5:eca18246329f8e6c05154323f7af677a",
         "BIFROST-simulation-lookup-table.h5": "md5:0a4df8039b9610df80fb7bd567736eeb",
         "coda_bifrost_999999_00026862.stripped.hdf": (
             "md5:bab18faa48de3b4617332a24dacd58a2"
         ),
     },
-    version="10",
+    version="11",
 )
 
 

packages/essspectroscopy/src/ess/bifrost/detector.py

@@ -192,6 +192,18 @@ def _fold_detector_to_arc_and_channel(
         folded.coords['channel'] = sc.array(
             dims=['channel'], values=channels[:n_channels], unit=None
         )
+
+        # Transpose to make `detector_number` contiguous:
+        detector_dims = ['arc', 'tube', 'channel', 'length']
+        target_dims = [
+            *(d for d in folded.dims if d not in detector_dims),
+            *detector_dims,
+        ]
+        folded = folded.transpose(target_dims).copy()
+        for name, coord in folded.coords.items():
+            folded.coords[name] = coord.transpose(
+                [d for d in target_dims if d in coord.dims]
+            ).copy()
         return folded
     else:
         # Not a rectangular subset, cannot fold.

packages/essspectroscopy/tests/bifrost/workflow_test.py

@@ -20,6 +20,7 @@
     Analyzers,
     DataAtSample,
     ElasticMonitor,
+    EmptyDetector,
     EnergyQDetector,
     Filename,
     LookupTableFilename,
@@ -212,6 +213,21 @@ def test_simulation_workflow_produces_the_same_data_as_before(
     )
 
 
+def test_calibrated_detector_has_contiguous_detector_number() -> None:
+    # This test requires all detector pixels.
+    # (the `workflow` fixture only uses the first 10.)
+    workflow = bifrost.BifrostSimulationWorkflow()
+    workflow[Filename[SampleRun]] = simulated_elastic_incoherent_with_phonon()
+
+    detector = workflow.compute(EmptyDetector[SampleRun])
+    detector_number = detector.coords['detector_number']
+    # Both the memory layout and the actual values should be contiguous
+    assert detector_number.values.flags['C_CONTIGUOUS']
+
+    flat = detector_number.flatten(to='x')
+    sc.testing.assert_identical(flat, sc.arange('x', 1, 1 + len(flat), unit=None))
+
+
 @pytest.fixture
 def coda_workflow(detector_names: list[str]) -> sciline.Pipeline:
     workflow = bifrost.BifrostWorkflow()