From 634e364cca15d0a6d35320b2ba23abf0a3cdd9a5 Mon Sep 17 00:00:00 2001
From: Florian Pfaff <6773539+FlorianPfaff@users.noreply.github.com>
Date: Wed, 1 Jul 2026 21:42:31 +0200
Subject: [PATCH 1/3] Add track identity F1 patch helper

---
 .../utils/track_evaluation/_identity_f1.py    | 39 +++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 src/pyrecest/utils/track_evaluation/_identity_f1.py

diff --git a/src/pyrecest/utils/track_evaluation/_identity_f1.py b/src/pyrecest/utils/track_evaluation/_identity_f1.py
new file mode 100644
index 000000000..0019fc261
--- /dev/null
+++ b/src/pyrecest/utils/track_evaluation/_identity_f1.py
@@ -0,0 +1,39 @@
+"""Local identity-set F1 fixes for track-evaluation exports."""
+
+from __future__ import annotations
+
+from typing import Any
+
+
+def patch_identity_f1(namespace: dict[str, Any]) -> None:
+    """Install an identity-set scorer with a zero-valued disjoint F1."""
+
+    safe_ratio = namespace["_safe_ratio"]
+    zero_ratio = namespace["_zero_ratio"]
+
+    def score_identity_sets(
+        predicted: set[Any],
+        reference: set[Any],
+        *,
+        prefix: str,
+        predicted_total_name: str,
+        reference_total_name: str,
+    ) -> dict[str, float | int]:
+        true_positives = len(predicted & reference)
+        false_positives = len(predicted - reference)
+        false_negatives = len(reference - predicted)
+        precision = safe_ratio(true_positives, true_positives + false_positives)
+        recall = safe_ratio(true_positives, true_positives + false_negatives)
+        f1 = zero_ratio(2.0 * precision * recall, precision + recall)
+        return {
+            f"{prefix}_true_positives": true_positives,
+            f"{prefix}_false_positives": false_positives,
+            f"{prefix}_false_negatives": false_negatives,
+            f"{prefix}_precision": precision,
+            f"{prefix}_recall": recall,
+            f"{prefix}_f1": f1,
+            predicted_total_name: len(predicted),
+            reference_total_name: len(reference),
+        }
+
+    namespace["_score_identity_sets"] = score_identity_sets

From 220074f1e410230d480166e5e6c84c6a1d4e03aa Mon Sep 17 00:00:00 2001
From: Florian Pfaff <6773539+FlorianPfaff@users.noreply.github.com>
Date: Wed, 1 Jul 2026 21:43:03 +0200
Subject: [PATCH 2/3] Use zero-valued F1 for disjoint track identity sets

---
 src/pyrecest/utils/track_evaluation/__init__.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/pyrecest/utils/track_evaluation/__init__.py b/src/pyrecest/utils/track_evaluation/__init__.py
index 13220f760..65d2fdcaf 100644
--- a/src/pyrecest/utils/track_evaluation/__init__.py
+++ b/src/pyrecest/utils/track_evaluation/__init__.py
@@ -3,6 +3,8 @@
 
 import numpy as np
 
+from ._identity_f1 import patch_identity_f1
+
 d = runpy.run_path(
     str(Path(__file__).resolve().parents[1] / "track_evaluation.py"), run_name=__name__
 )
@@ -20,6 +22,7 @@ def f(v):
 
 
 d["_optional_int_candidate"] = f
+patch_identity_f1(d)
 for n in d["__all__"]:
     globals()[n] = d[n]
 __all__ = d["__all__"]

From 0abca65e54fd98da1cb1c715f1b2435607df5cf8 Mon Sep 17 00:00:00 2001
From: Florian Pfaff <6773539+FlorianPfaff@users.noreply.github.com>
Date: Wed, 1 Jul 2026 21:43:17 +0200
Subject: [PATCH 3/3] Add regression for disjoint track identity F1

---
 tests/test_track_evaluation_identity_f1.py | 31 ++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 tests/test_track_evaluation_identity_f1.py

diff --git a/tests/test_track_evaluation_identity_f1.py b/tests/test_track_evaluation_identity_f1.py
new file mode 100644
index 000000000..b41dd4e21
--- /dev/null
+++ b/tests/test_track_evaluation_identity_f1.py
@@ -0,0 +1,31 @@
+from pyrecest.utils.track_evaluation import score_complete_tracks, score_track_links
+
+
+def test_disjoint_track_identity_sets_have_zero_f1():
+    complete_scores = score_complete_tracks([[0, 1]], [[2, 3]])
+
+    assert complete_scores["complete_track_true_positives"] == 0
+    assert complete_scores["complete_track_false_positives"] == 1
+    assert complete_scores["complete_track_false_negatives"] == 1
+    assert complete_scores["complete_track_precision"] == 0.0
+    assert complete_scores["complete_track_recall"] == 0.0
+    assert complete_scores["complete_track_f1"] == 0.0
+
+    link_scores = score_track_links([[0, 1]], [[2, 3]])
+
+    assert link_scores["track_link_true_positives"] == 0
+    assert link_scores["track_link_false_positives"] == 1
+    assert link_scores["track_link_false_negatives"] == 1
+    assert link_scores["track_link_precision"] == 0.0
+    assert link_scores["track_link_recall"] == 0.0
+    assert link_scores["track_link_f1"] == 0.0
+
+
+def test_empty_track_identity_sets_keep_perfect_precision_recall_and_f1():
+    scores = score_complete_tracks([[None, None]], [[None, None]])
+
+    assert scores["complete_tracks"] == 0
+    assert scores["reference_complete_tracks"] == 0
+    assert scores["complete_track_precision"] == 1.0
+    assert scores["complete_track_recall"] == 1.0
+    assert scores["complete_track_f1"] == 1.0