More robust for LOS

slsim/ParamDistributions/kext_gext_distributions.py

@@ -100,7 +100,8 @@ def get_kappa_gamma(self, z_source, z_lens, use_nonlinear_correction=False):
         :param use_nonlinear_correction: Boolean to use the nonlinear correction data.
         :return: Tuple of gamma and kappa values.
         """
-
+        if z_source <= z_lens:
+            return 0.0, 0.0
         z_source_rounded = self._round_to_nearest_0_1(z_source)
         z_lens_rounded = self._round_to_nearest_0_1(z_lens)
         if z_lens_rounded == z_source_rounded:

tests/test_kext_gext_distributions.py

@@ -50,6 +50,11 @@ def test_valid_inputs():
     assert isinstance(result2[0], float)
     assert isinstance(result2[1], float)
 
+    result3 = line_of_sight.get_kappa_gamma(0.3, 0.4)
+    assert isinstance(result3, tuple)
+    assert len(result3) == 2
+    assert result3[0] == 0.0
+
 
 def test_invalid():
     with pytest.raises(FileNotFoundError):