4 files changed, 29 insertions, 3 deletions
diff --git a/fg21sim/extragalactic/__init__.py b/fg21sim/extragalactic/__init__.py
index 01c52e9..89d23b0 100644
--- a/fg21sim/extragalactic/__init__.py
+++ b/fg21sim/extragalactic/__init__.py
@@ -1,5 +1,5 @@
 # Copyright (c) 2016 Weitian LI <liweitianux@live.com>
 # MIT license
 
-from .clusters import GalaxyClusters
-from .pointsources import PointSources
+# from .clusters import GalaxyClusters
+# from .pointsources import PointSources
diff --git a/fg21sim/extragalactic/clusters/__init__.py b/fg21sim/extragalactic/clusters/__init__.py
index af976ca..1eb7bae 100644
--- a/fg21sim/extragalactic/clusters/__init__.py
+++ b/fg21sim/extragalactic/clusters/__init__.py
@@ -1,4 +1,4 @@
 # Copyright (c) 2016 Weitian LI <liweitianux@live.com>
 # MIT license
 
-from .clusters import GalaxyClusters
+# from .clusters import GalaxyClusters
diff --git a/fg21sim/extragalactic/clusters/main.py b/fg21sim/extragalactic/clusters/main.py
new file mode 100644
index 0000000..8f7f8e7
--- /dev/null
+++ b/fg21sim/extragalactic/clusters/main.py
@@ -0,0 +1,24 @@
+# Copyright (c) 2017 Weitian LI <liweitianux@live.com>
+# MIT license
+
+"""
+Simulate (giant) radio halos of galaxy clusters as one of the
+foreground components.
+"""
+
+import logging
+
+import numpy as np
+
+from .halo import HaloSingle
+
+
+logger = logging.getLogger(__name__)
+
+
+class Halos:
+    """
+    Simulate (giant) radio halos of galaxy clusters as one of the
+    foreground components.
+    """
+    pass
diff --git a/fg21sim/extragalactic/clusters/mergertree.py b/fg21sim/extragalactic/clusters/mergertree.py
index 61b9542..5891dba 100644
--- a/fg21sim/extragalactic/clusters/mergertree.py
+++ b/fg21sim/extragalactic/clusters/mergertree.py
@@ -73,6 +73,8 @@ def plot_mtree(mtree, outfile, figsize=(12, 8)):
     """
     Plot the cluster merger tree.
 
+    TODO/XXX: This function needs significant speed optimization!
+
     Parameters
     ----------
     mtree : `~MergerTree`