Reset CLEAR continuity after unmatched frames

src/pyrecest/evaluation/tracking_metrics/_clear_identity.py

@@ -46,9 +46,11 @@ def evaluate_clear(data: TrackingSequence, *, threshold: float) -> ClearCounts:
     ):
         if len(gt_ids) == 0:
             fp += len(tracker_ids)
+            previous_timestep_id[:] = np.nan
             continue
         if len(tracker_ids) == 0:
             fn += len(gt_ids)
+            previous_timestep_id[:] = np.nan
             continue
         continuity = tracker_ids[np.newaxis, :] == previous_timestep_id[gt_ids[:, None]]
         score = continuity.astype(float) * 1000.0 + similarity

tests/evaluation/test_tracking_metrics.py

@@ -82,6 +82,26 @@ def test_identity_switch_reduces_association_metrics() -> None:
     assert finalize_identity(identity_counts)["idf1"] == pytest.approx(0.5)
 
 
+def test_clear_continuity_does_not_cross_unmatched_frames() -> None:
+    data = _sequence(
+        [[0, 1], [0, 1], [0, 1]],
+        [[0, 1], [], [0, 1]],
+        [
+            [[1.0, 0.0], [0.0, 1.0]],
+            [[], []],
+            [[0.6, 0.9], [0.9, 0.6]],
+        ],
+        num_gt_ids=2,
+        num_tracker_ids=2,
+    )
+
+    counts = evaluate_clear(data, threshold=0.5)
+
+    assert (counts.tp, counts.fp, counts.fn) == (4, 0, 2)
+    assert counts.id_switches == 2
+    assert counts.motp_sum == pytest.approx(3.8)
+
+
 def test_hota_uses_multiple_localization_thresholds() -> None:
     data = _sequence(
         [[0]],