changes to the test

theano/sandbox/scan_module/tests/test_scan.py

@@ -25,9 +25,37 @@ class TestScan(unittest.TestCase):
     def setUp(self):
         utt.seed_rng()
 
+    def test001_scan_removed_nsteps_1(self):
+        def f_pow2(x_tm1):
+            return 2 * x_tm1
+        state = theano.tensor.scalar('state')
+        output, updates = scan_module.scan(f_pow2,
+                                           [],
+                                           state,
+                                           [],
+                                           n_steps=1,
+                                           truncate_gradient=-1,
+                                           go_backwards=False)
+
+        my_f = theano.function([state, n_steps],
+                               output,
+                               updates=updates,
+                               allow_input_downcast=True)
+        assert len([x for x in my_f.maker.env.toposort()
+                    if isinstance(x.op, scan_module.scan_op.ScanOp)])
+
+        rng = numpy.random.RandomState(utt.fetch_seed())
+        state = rng.uniform()
+        steps = 1
+
+        numpy_values = numpy.array([state * (2 ** (k + 1)) for k
+                                    in xrange(steps)])
+        theano_values = my_f(state, steps)
+        assert numpy.allclose(numpy_values, theano_values)
+
     # generator network, only one output , type scalar ; no sequence or
     # non sequence arguments
-    def test001_generator_one_scalar_output(self):
+    def test002_generator_one_scalar_output(self):
         def f_pow2(x_tm1):
             return 2 * x_tm1
         state = theano.tensor.scalar('state')