chore: import upstream snapshot with attribution

books/PRML/PRML-master-Python/test/nn/array/split.py

@@ -0,0 +1,21 @@
+import unittest
+import numpy as np
+from prml import nn
+
+
+class TestSplit(unittest.TestCase):
+
+    def test_split(self):
+        x = np.random.rand(10, 7)
+        a = nn.Parameter(x)
+        b, c = nn.split(a, (3,), axis=-1)
+        self.assertTrue((b.value == x[:, :3]).all())
+        self.assertTrue((c.value == x[:, 3:]).all())
+        b.backward(np.ones((10, 3)))
+        self.assertIs(a.grad, None)
+        c.backward(np.ones((10, 4)))
+        self.assertTrue((a.grad == np.ones((10, 7))).all())
+
+
+if __name__ == '__main__':
+    unittest.main()