From bb764b960a1a6f745f9eaed7aea2f65fa6eb6b72 Mon Sep 17 00:00:00 2001
From: Jonathan Shimwell <mail@jshimwell.com>
Date: Mon, 8 Aug 2022 13:52:50 +0100
Subject: [PATCH] added return type to bin width method

---
 openmc/filter.py | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/openmc/filter.py b/openmc/filter.py
index 7fe454865..2e6c22c3a 100644
--- a/openmc/filter.py
+++ b/openmc/filter.py
@@ -1325,8 +1325,14 @@ class EnergyFilter(RealFilter):
             cv.check_greater_than('filter value', v1, 0., equality=True)
 
     def bin_log_width(self):
-        """Returns the base 10 log width of energy bins which is useful when
-        plotting the normalized flux"""
+        """Calculates the base 10 log width of energy bins which is useful when
+        plotting the normalized flux.
+
+        Returns
+        -------
+        numpy.array
+            Array of bin widths
+        """
         bin_edges = np.unique(self.bins)
         log_width = np.log10(bin_edges[1:]/bin_edges[:-1])
         return log_width