From 8cb0dca81358a911c3b221b8cd6acc335eeb726b Mon Sep 17 00:00:00 2001
From: Jingang Liang <liangjg2008@gmail.com>
Date: Sat, 10 Oct 2020 09:37:43 +0800
Subject: [PATCH] fix complex to float casting error

---
 openmc/data/multipole.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/openmc/data/multipole.py b/openmc/data/multipole.py
index 2dfc94ca26..ae7145774e 100644
--- a/openmc/data/multipole.py
+++ b/openmc/data/multipole.py
@@ -243,8 +243,8 @@ def _vectfit_xs(energy, ce_xs, mts, rtol=1e-3, atol=1e-5, orders=None,
         if log:
             print("Order={}({}/{})".format(order, i, len(orders)))
         # initial guessed poles
-        poles = np.linspace(s[0], s[-1], order//2)
-        poles += poles*0.01j
+        poles_r = np.linspace(s[0], s[-1], order//2)
+        poles = poles_r + poles_r*0.01j
         poles = np.sort(np.append(poles, np.conj(poles)))
 
         found_better = False