Added unit-test for transfering random states between theano graphs

theano/sandbox/test_rng_mrg.py

@@ -678,7 +678,8 @@ class T_MRG(unittest.TestCase):
             self.assertRaises(ValueError, R.multinomial, size, 1, [])
             self.assertRaises(ValueError, R.normal, size)
 
-def test_multiple_rng():
+
+def test_multiple_rng_aliasing():
     """
     Test that when we have multiple random number generators, we do not alias
     the state_updates member. `state_updates` can be useful when attempting to
@@ -689,3 +690,23 @@ def test_multiple_rng():
     rng1 = MRG_RandomStreams(1234)
     rng2 = MRG_RandomStreams(2392)
     assert rng1.state_updates is not rng2.state_updates
+
+
+def test_random_state_transfer():
+    """
+    Test that random state can be transferred from one theano graph to another.
+    """
+    class Graph():
+        def __init__(self, seed=123):
+            self.rng = MRG_RandomStreams(seed)
+            self.y = self.rng.uniform(size=(1,))
+    g1 = Graph(seed=123)
+    f1 = theano.function([], g1.y)
+    g2 = Graph(seed=987)
+    f2 = theano.function([], g2.y)
+
+    g2.rng.rstate = g1.rng.rstate
+    for (su1, su2) in zip(g1.rng.state_updates, g2.rng.state_updates):
+        su2[0].set_value(su1[0].get_value())
+
+    numpy.testing.assert_array_almost_equal(f1(), f2(), decimal=6)

theano/tensor/tests/test_shared_randomstreams.py

@@ -715,7 +715,7 @@ class T_SharedRandomStreams(unittest.TestCase):
         s_rng.set_value(rr, borrow=True)
         assert rr is s_rng.container.storage[0]
 
-    def test_multiple_rng(self):
+    def test_multiple_rng_aliasing(self):
         """
         Test that when we have multiple random number generators, we do not alias
         the state_updates member. `state_updates` can be useful when attempting to
@@ -728,6 +728,24 @@ class T_SharedRandomStreams(unittest.TestCase):
         assert rng1.state_updates is not rng2.state_updates
         assert rng1.gen_seedgen is not rng2.gen_seedgen
 
+    def test_random_state_transfer(self):
+        """
+        Test that random state can be transferred from one theano graph to another.
+        """
+        class Graph():
+            def __init__(self, seed=123):
+                self.rng = RandomStreams(seed)
+                self.y = self.rng.uniform(size=(1,))
+        g1 = Graph(seed=123)
+        f1 = function([], g1.y)
+        g2 = Graph(seed=987)
+        f2 = function([], g2.y)
+
+        for (su1, su2) in zip(g1.rng.state_updates, g2.rng.state_updates):
+            su2[0].set_value(su1[0].get_value())
+
+        numpy.testing.assert_array_almost_equal(f1(), f2(), decimal=6)
+
 
 if __name__ == '__main__':
     from theano.tests import main