Fix tickets #921 and #923. Add regression tests.

2 files changed, 34 insertions, 12 deletions

diff --git a/numpy/random/mtrand/distributions.c b/numpy/random/mtrand/distributions.c
index 08a0d49f1..d138be948 100644
--- a/numpy/random/mtrand/distributions.c
+++ b/numpy/random/mtrand/distributions.c
@@ -814,7 +814,7 @@ long rk_hypergeometric_hrua(rk_state *state, long good, long bad, long sample)
     if (good > bad) Z = m - Z;
     
     /* another fix from rv.py to allow sample to exceed popsize/2 */
-    if (m < sample) Z = bad - Z;
+    if (m < sample) Z = good - Z;
     
     return Z;
 }
@@ -876,7 +876,7 @@ long rk_logseries(rk_state *state, double p)
                 return result;
             }
         }
-        if (V <= q) {
+        if (V >= q) {
             return 1;
         }
         return 2;
diff --git a/numpy/random/tests/test_random.py b/numpy/random/tests/test_random.py
index 9d3de27e2..b316d7b79 100644
--- a/numpy/random/tests/test_random.py
+++ b/numpy/random/tests/test_random.py
@@ -2,6 +2,38 @@ from numpy.testing import *
 from numpy import random
 import numpy as np
 
+class TestRegression(TestCase):
+
+    def test_VonMises_range(self):
+        """Make sure generated random variables are in [-pi, pi].
+
+        Regression test for ticket #986.
+        """
+        for mu in np.linspace(-7., 7., 5):
+            r = random.mtrand.vonmises(mu,1,50)
+            assert np.all(r > -np.pi) and np.all(r <= np.pi)
+
+    def test_hypergeometric_range(self) :
+        """Test for ticket #921"""
+        assert_(np.all(np.random.hypergeometric(3, 18, 11, size=10) < 4))
+        assert_(np.all(np.random.hypergeometric(18, 3, 11, size=10) > 0))
+
+    def test_logseries_convergence(self) :
+        """Test for ticket #923"""
+        N = 100000
+        rvsn = np.random.logseries(0.8, size=N)
+        # these two frequency counts should be close to theoretical
+        # numbers with this large sample
+        # theoretical large N result is 0.49706795
+        freq = np.sum(rvsn == 1) / float(N)
+        msg = "Obsevered frequency was %f, should be > 0.45" % freq
+        assert_(freq > 0.45, msg)
+        # theoretical large N result is 0.19882718
+        freq = np.sum(rvsn == 2) / float(N)
+        msg = "Obsevered frequency was %f, should be < 0.23" % freq
+        assert_(freq < 0.23, msg)
+
+
 class TestMultinomial(TestCase):
     def test_basic(self):
         random.multinomial(100, [0.2, 0.8])
@@ -15,16 +47,6 @@ class TestMultinomial(TestCase):
         assert np.all(-5 <= x)
         assert np.all(x < -1)
 
-class TestVonMises(TestCase):
-    def test_output_domain(self):
-        """Make sure generated random variables are in [-pi, pi].
-
-        Regression test for ticket #986.
-        """
-        for mu in np.linspace(-7., 7., 5):        
-            r = random.mtrand.vonmises(mu,1,50)
-            assert np.all(r>-np.pi) and np.all(r<=np.pi)
-
 
 
 class TestSetState(TestCase):