修改为东南天坐标系

backend_service/venv/lib/python3.13/site-packages/nltk/lm/util.py

@@ -0,0 +1,19 @@
+# Natural Language Toolkit
+#
+# Copyright (C) 2001-2025 NLTK Project
+# Author: Ilia Kurenkov <ilia.kurenkov@gmail.com>
+# URL: <https://www.nltk.org/>
+# For license information, see LICENSE.TXT
+"""Language Model Utilities"""
+
+from math import log
+
+NEG_INF = float("-inf")
+POS_INF = float("inf")
+
+
+def log_base2(score):
+    """Convenience function for computing logarithms with base 2."""
+    if score == 0.0:
+        return NEG_INF
+    return log(score, 2)