Merge pull request #2732 from cta-observatory/fix-muon-param-writing

Author: kosack

docs/changes/2732.bugfix.rst

@@ -0,0 +1 @@
+Fix units (absence of) for skewness and excess kurtosis in muon analysis

src/ctapipe/image/muon/features.py

@@ -324,23 +324,19 @@ def radial_light_distribution(
     if np.sum(image) == 0:
         return (
             np.nan * u.deg,
-            np.nan * u.dimensionless_unscaled,
-            np.nan * u.dimensionless_unscaled,
+            np.nan,
+            np.nan,
         )
 
     pixel_r = np.hypot(pixel_fov_lon - center_fov_lon, pixel_fov_lat - center_fov_lat)
 
     mean = np.average(pixel_r, weights=image)
     delta_r = pixel_r - mean
     radial_std_dev = np.sqrt(np.average(delta_r**2, weights=image))
-    skewness = (
-        np.average(delta_r**3, weights=image)
-        / radial_std_dev**3
-        * u.dimensionless_unscaled
-    )
+    skewness = (np.average(delta_r**3, weights=image) / radial_std_dev**3).to_value()
     excess_kurtosis = (
         np.average(delta_r**4, weights=image) / radial_std_dev**4 - 3.0
-    ) * u.dimensionless_unscaled
+    ).to_value()
 
     return (
         radial_std_dev,

src/ctapipe/image/muon/tests/test_muon_features.py

@@ -142,6 +142,12 @@ def test_radial_light_distribution():
     )
 
     assert radial_std_dev.unit == u.deg
+    assert isinstance(
+        skewness, (float, np.floating)
+    ), f"Unexpected type: {type(skewness)}"
+    assert isinstance(
+        excess_kurtosis, (float, np.floating)
+    ), f"Unexpected type: {type(excess_kurtosis)}"
     assert np.isclose(radial_std_dev, expected_std_dev, atol=1e-2)
     assert np.isclose(skewness, expected_skewness, atol=1e-2)
     assert np.isclose(excess_kurtosis, expected_excess_kurtosis, atol=1e-2)