TST: add test for broadcasting in stats.nct distribution.

scipy/stats/distributions.py

@@ -4844,6 +4844,7 @@ class nct_gen(rv_continuous):
     """
     def _argcheck(self, df, nc):
         return (df > 0) & (nc == nc)
+
     def _rvs(self, df, nc):
         return norm.rvs(loc=nc,size=self._size)*sqrt(df) / sqrt(chi2.rvs(df,size=self._size))
 

scipy/stats/tests/test_distributions.py

@@ -870,6 +870,23 @@ def test_poisson(self):
         assert_almost_equal(prob_lb, 1, decimal=14)
 
 
+class TestNct(TestCase):
+    def test_nc_parameter(self):
+        # Parameter values c<=0 were not enabled (gh-2402).
+        # For negative values c and for c=0 results of rv.cdf(0) below were nan
+        rv = stats.nct(5, 0)
+        assert_equal(rv.cdf(0), 0.5)
+        rv = stats.nct(5, -1)
+        assert_almost_equal(rv.cdf(0), 0.841344746069, decimal=10)
+
+    def test_broadcasting(self):
+        res = stats.nct.pdf(5, np.arange(4,7)[:,None], np.linspace(0.1, 1, 4))
+        expected = array([[ 0.00321886,  0.00557466,  0.00918418,  0.01442997],
+                          [ 0.00217142,  0.00395366,  0.00683888,  0.01126276],
+                          [ 0.00153078,  0.00291093,  0.00525206,  0.00900815]])
+        assert_allclose(res, expected, rtol=1e-5)
+
+
 def test_regression_ticket_1316():
     # The following was raising an exception, because _construct_default_doc()
     # did not handle the default keyword extradoc=None.  See ticket #1316.
@@ -1144,14 +1161,5 @@ def test_foldnorm_zero():
     assert_equal(rv.cdf(0), 0)  # rv.cdf(0) previously resulted in: nan
 
 
-def test_nct_ticket_1883():
-    # Parameter values c<=0 were not enabled
-    # For negative values c and for c=0 results of rv.cdf(0) below were nan
-    rv = stats.nct(5, 0)
-    assert_equal(rv.cdf(0), 0.5)
-    rv = stats.nct(5, -1)
-    assert_almost_equal(rv.cdf(0), 0.841344746069, decimal=10)
-
-
 if __name__ == "__main__":
     run_module_suite()