Merge pull request #2593 from michaelosthege/patch-2

inclusiver upper bound on DiscreteUniform fixes #2592

Author: fonnesbeck

pymc3/distributions/discrete.py

@@ -447,9 +447,8 @@ def __init__(self, lower, upper, *args, **kwargs):
     def _random(self, lower, upper, size=None):
         # This way seems to be the only to deal with lower and upper
         # as array-like.
-        samples = stats.uniform.rvs(lower, upper - lower - np.finfo(float).eps,
-                                    size=size)
-        return np.floor(samples).astype('int32')
+        samples = stats.randint.rvs(lower, upper + 1, size=size)
+        return samples
 
     def random(self, point=None, size=None, repeat=None):
         lower, upper = draw_values([self.lower, self.upper], point=point)

pymc3/tests/test_distributions_random.py

@@ -506,7 +506,7 @@ def test_geometric(self):
 
     def test_discrete_uniform(self):
         def ref_rand(size, lower, upper):
-            return st.randint.rvs(lower, upper, size=size)
+            return st.randint.rvs(lower, upper + 1, size=size)
         pymc3_random_discrete(pm.DiscreteUniform, {'lower': -NatSmall, 'upper': NatSmall},
                               ref_rand=ref_rand)