Add symmetric log1p to tfr.utils.

PiperOrigin-RevId: 392758538
forrestgg · Oct 18, 2021 · 65fd6e7 · 65fd6e7
1 parent e6ed9a9
commit 65fd6e7
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diff --git a/tensorflow_ranking/python/keras/utils.py b/tensorflow_ranking/python/keras/utils.py
@@ -44,3 +44,9 @@ def log2_inverse(rank):
 @tf.keras.utils.register_keras_serializable(package="tensorflow_ranking")
 def is_greater_equal_1(label):
   return tf.greater_equal(label, 1.0)
+
+
+@tf.keras.utils.register_keras_serializable(package="tensorflow_ranking")
+def symmetric_log1p(t):
+  return tf.math.log1p(t * tf.sign(t)) * tf.sign(t)
+
diff --git a/tensorflow_ranking/python/keras/utils_test.py b/tensorflow_ranking/python/keras/utils_test.py
@@ -27,6 +27,7 @@ def test_functions_are_serializable(self):
         utils.pow_minus_1,
         utils.log2_inverse,
         utils.is_greater_equal_1,
+        utils.symmetric_log1p,
     ]:
       self.assertIsNotNone(tf.keras.utils.serialize_keras_object(fn))
 
@@ -36,6 +37,7 @@ def test_functions_are_callable(self):
     self.assertEqual(utils.pow_minus_1(1.0), 1.0)
     self.assertEqual(utils.log2_inverse(1.0), 1.0)
     self.assertEqual(utils.is_greater_equal_1(1.0), True)
+    self.assertAllClose(utils.symmetric_log1p(-1.0), -0.69314718056)
 
 
 if __name__ == '__main__':