From b3a2456f2b2033f8eeee6f84ce69e757022918e3 Mon Sep 17 00:00:00 2001
From: rlbarker <rosiebarker1@hotmail.com>
Date: Mon, 26 Feb 2024 22:15:50 +0000
Subject: [PATCH] Added checks that tolerance value is between 0 and 1 (#2884)

---
 openmc/stats/univariate.py     | 3 +++
 tests/unit_tests/test_stats.py | 6 ++++++
 2 files changed, 9 insertions(+)

diff --git a/openmc/stats/univariate.py b/openmc/stats/univariate.py
index b33f88af86..e7ff64257a 100644
--- a/openmc/stats/univariate.py
+++ b/openmc/stats/univariate.py
@@ -280,6 +280,9 @@ class Discrete(Univariate):
         Discrete distribution with low-importance points removed
 
         """
+        cv.check_less_than("tolerance", tolerance, 1.0, equality=True)
+        cv.check_greater_than("tolerance", tolerance, 0.0, equality=True)
+
         # Determine (reversed) sorted order of probabilities
         intensity = self.p * self.x
         index_sort = np.argsort(intensity)[::-1]
diff --git a/tests/unit_tests/test_stats.py b/tests/unit_tests/test_stats.py
index 8438535ff8..f5368e912f 100644
--- a/tests/unit_tests/test_stats.py
+++ b/tests/unit_tests/test_stats.py
@@ -89,6 +89,12 @@ def test_clip_discrete():
     d_same = d.clip(1e-6, inplace=True)
     assert d_same is d
 
+    with pytest.raises(ValueError):
+        d.clip(-1.)
+    
+    with pytest.raises(ValueError):
+        d.clip(5)
+
 
 def test_uniform():
     a, b = 10.0, 20.0