From 9fe745b0b4b54eecd2e73ca13ff091607dd9cc54 Mon Sep 17 00:00:00 2001
From: rstiskalek <richard.stiskalek@protonmail.com>
Date: Fri, 25 Nov 2022 10:54:09 +0000
Subject: [PATCH] add center of mass

---
 csiborgtools/fits/halo.py | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/csiborgtools/fits/halo.py b/csiborgtools/fits/halo.py
index 596e8ef..c79a60a 100644
--- a/csiborgtools/fits/halo.py
+++ b/csiborgtools/fits/halo.py
@@ -425,8 +425,7 @@ class Clump:
 
         Returns
         -------
-        m : 1-dimensional array
-            Array of shape `(n_particles, )`.
+        m : 1-dimensional array of shape `(n_particles, )`
         """
         return self._m
 
@@ -437,6 +436,17 @@ class Clump:
             raise TypeError("`r` and `m` must be equal size 1-dim arrays.")
         self._m = m
 
+    @property
+    def center_mass(self):
+        """
+        Clump center of mass.
+
+        Returns
+        -------
+        cm : 1-dimensional array
+        """
+        return numpy.average(self.pos, axis=0, weights=self.m)
+
     @property
     def index(self):
         """