update test_rotate.py

tests/transforms_tests/image_tests/test_rotate.py

@@ -1,23 +1,25 @@
+import random
 import unittest
 
 import numpy as np
 
 from chainer import testing
+from chainercv.transforms import flip
 from chainercv.transforms import rotate
 
 
-@testing.parameterize(*testing.product({
-    'k': [0, 1, 2, 3]
-}))
 class TestRotate(unittest.TestCase):
 
     def test_rotate(self):
         img = np.random.uniform(size=(3, 32, 24))
+        angle = random.uniform(0, 180)
 
-        out = rotate(img, self.k)
-        out = rotate(out, 4 - self.k)
+        out = rotate(img, angle)
+        expected = flip(img, x_flip=True)
+        expected = rotate(expected, -1 * angle)
+        expected = flip(expected, x_flip=True)
 
-        np.testing.assert_equal(img, out)
+        np.testing.assert_almost_equal(out, expected, decimal=6)
 
 
 testing.run_module(__name__, __file__)