clusters: Halo templates are normalized to have mean of 1

Also update the documents of "draw_halo()" function

Signed-off-by: Aaron LI <aly@aaronly.me>

2 files changed, 12 insertions, 4 deletions

diff --git a/fg21sim/extragalactic/clusters/helper.py b/fg21sim/extragalactic/clusters/helper.py
index becb608..26146cc 100644
--- a/fg21sim/extragalactic/clusters/helper.py
+++ b/fg21sim/extragalactic/clusters/helper.py
@@ -449,15 +449,23 @@ def draw_halo(rprofile, felong, rotation=0.0):
 
     Parameters
     ----------
-    rprofile
+    rprofile : 1D `~numpy.ndarray`
+        The values along the radial pixels (0, 1, 2, ...),
+        e.g., calculated by the above ``halo_rprofile()``.
+    felong : float
+        The elongated fraction of the elliptical halo, which is
+        defined as the ratio of semi-minor axis to the semi-major axis.
+    rotation : float
+        The rotation angle of the elliptical halo.
+        Unit: [deg]
 
     Returns
     -------
     image : 2D `~numpy.ndarray`
         2D array of the drawn halo template image.
-        The image is normalized to have sum of 1.
+        The image is normalized to have *mean* value of 1.
     """
     image = circle(rprofile=rprofile)
     image = circle2ellipse(image, bfraction=felong, rotation=rotation)
-    image /= image.sum()
+    image /= image.mean()
     return image
diff --git a/fg21sim/extragalactic/clusters/main.py b/fg21sim/extragalactic/clusters/main.py
index 15a9dcd..94a3288 100644
--- a/fg21sim/extragalactic/clusters/main.py
+++ b/fg21sim/extragalactic/clusters/main.py
@@ -304,7 +304,7 @@ class GalaxyClusters:
         ----
         The drawn template images are append to the dictionaries of
         the corresponding halo within the ``self.halos``.
-        The templates are normalized to have sum of 1.
+        The templates are normalized to have *mean* value of 1.
         """
         num = len(self.halos)
         logger.info("Draw template images for %d halos ..." % num)