Test the default_update behavior of shared random streams.

theano/tensor/tests/test_shared_randomstreams.py

@@ -201,6 +201,55 @@ class T_SharedRandomStreams(unittest.TestCase):
         self.assertRaises(TypeError, f1, in_mval)
         self.assertRaises(TypeError, f, in_vval)
 
+    def test_default_updates(self):
+        # Basic case: default_updates
+        random_a = RandomStreams(234)
+        out_a = random_a.uniform((2,2))
+        fn_a = function([], out_a)
+        fn_a_val0 = fn_a()
+        fn_a_val1 = fn_a()
+        assert not numpy.all(fn_a_val0 == fn_a_val1)
+
+        nearly_zeros = function([], out_a + out_a - 2 * out_a)
+        assert numpy.all(abs(nearly_zeros()) < 1e-5)
+
+        # Explicit updates #1
+        random_b = RandomStreams(234)
+        out_b = random_b.uniform((2,2))
+        fn_b = function([], out_b, updates=random_b.updates())
+        fn_b_val0 = fn_b()
+        fn_b_val1 = fn_b()
+        assert numpy.all(fn_b_val0 == fn_a_val0)
+        assert numpy.all(fn_b_val1 == fn_a_val1)
+
+        # Explicit updates #2
+        random_c = RandomStreams(234)
+        out_c = random_c.uniform((2,2))
+        fn_c = function([], out_c, updates=[out_c.update])
+        fn_c_val0 = fn_c()
+        fn_c_val1 = fn_c()
+        assert numpy.all(fn_c_val0 == fn_a_val0)
+        assert numpy.all(fn_c_val1 == fn_a_val1)
+
+        # No updates at all
+        random_d = RandomStreams(234)
+        out_d = random_d.uniform((2,2))
+        fn_d = function([], out_d, no_default_updates=True)
+        fn_d_val0 = fn_d()
+        fn_d_val1 = fn_d()
+        assert numpy.all(fn_d_val0 == fn_a_val0)
+        assert numpy.all(fn_d_val1 == fn_d_val0)
+
+        # No updates for out
+        random_e = RandomStreams(234)
+        out_e = random_e.uniform((2,2))
+        fn_e = function([], out_e, no_default_updates=[out_e.rng])
+        fn_e_val0 = fn_e()
+        fn_e_val1 = fn_e()
+        assert numpy.all(fn_e_val0 == fn_a_val0)
+        assert numpy.all(fn_e_val1 == fn_e_val0)
+
+
 if __name__ == '__main__':
     from theano.tests import main
     main("test_randomstreams")