Fixed test_matinv to work for any seed

theano/tensor/tests/test_basic.py

@@ -1305,14 +1305,26 @@ class test_matinv(unittest.TestCase):
             ssd, gw = fn(x,w)
             #print ssd, x*w, x, w
             if i == 0:
-                str0 = str(ssd)
+                ssd0 = ssd
             w -= 0.4 * gw
 
-        return str0, str(ssd)
+        return ssd0, ssd
 
     def test_reciprocal(self):
         """Matrix reciprocal by gradient descent"""
-        self.assertEqual(('6.10141615619', '0.00703816291711'), self.mat_reciprocal(3))
+        ssd0,ssd = self.mat_reciprocal(3)
+
+        numpy.random.seed(unittest_tools.fetch_seed(1))
+        # hand-coded numpy implementation for verification
+        x = numpy.random.rand(3,3)+0.1
+        w = numpy.random.rand(3,3)
+        myssd0 = numpy.sum((x*w - numpy.ones((3,3)))**2.0)
+        for i in xrange(300):
+            gw = 2*(x*w - numpy.ones((3,3)))*x  # derivative of dMSE/dw
+            myssd = numpy.sum((x*w - numpy.ones((3,3)))**2)
+            w -= 0.4 * gw
+        self.failUnlessAlmostEqual(ssd0, myssd0)
+        self.failUnlessAlmostEqual(ssd, myssd)
 
 class t_dot(unittest.TestCase):
     def setUp(self):