New interface for scan

theano/sandbox/test_scan.py

+import theano
+import numpy
+import scan
+
+
+def test_001():
+    x0 = theano.tensor.fvector('x0')
+    state = theano.tensor.unbroadcast(
+        theano.tensor.shape_padleft(x0), 0)
+    out, _ = scan.scan(lambda x:x+numpy.float32(1),
+                           states = state,
+                           n_steps = 5)
+    fn = theano.function([x0], out[0])
+    val_x0 = numpy.float32([1,2,3])
+    assert numpy.all(fn(val_x0) == val_x0 +5)
+
+
+def test_002():
+    x0 = theano.tensor.fvector('x0')
+    state = theano.tensor.alloc(
+        theano.tensor.constant(numpy.float32(0)),
+        6,
+        x0.shape[0])
+    state = theano.tensor.set_subtensor(state[0], x0)
+
+    out, _ = scan.scan(lambda x:x+numpy.float32(1),
+                           states = state,
+                           n_steps = 5)
+    fn = theano.function([x0], out)
+    val_x0 = numpy.float32([1,2,3])
+    assert numpy.all(fn(val_x0)[-1] == val_x0 +5)
+    assert numpy.all(fn(val_x0)[0] == val_x0)
+
+
+if __name__=='__main__':
+    test_001()
+    test_002()
+
+