chore: import upstream snapshot with attribution

books/PRML/PRML-master-Python/test/nn/nonlinear/sigmoid.py

@@ -0,0 +1,12 @@
+import unittest
+from prml import nn
+
+
+class TestSigmoid(unittest.TestCase):
+
+    def test_sigmoid(self):
+        self.assertEqual(nn.sigmoid(0).value, 0.5)
+
+
+if __name__ == '__main__':
+    unittest.main()

books/PRML/PRML-master-Python/test/nn/nonlinear/softmax.py

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+import unittest
+import numpy as np
+from prml import nn
+
+
+class TestSoftmax(unittest.TestCase):
+
+    def test_softmax(self):
+        self.assertTrue(np.allclose(nn.softmax(np.ones(4)).value, 0.25))
+
+
+if __name__ == '__main__':
+    unittest.main()

books/PRML/PRML-master-Python/test/nn/nonlinear/softplus.py

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+import unittest
+import numpy as np
+from prml import nn
+
+
+class TestSoftplus(unittest.TestCase):
+
+    def test_softplus(self):
+        self.assertEqual(nn.softplus(0).value, np.log(2))
+
+
+if __name__ == '__main__':
+    unittest.main()

books/PRML/PRML-master-Python/test/nn/nonlinear/tanh.py

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+import unittest
+from prml import nn
+
+
+class TestTanh(unittest.TestCase):
+
+    def test_tanh(self):
+        self.assertEqual(nn.tanh(0).value, 0)
+
+
+if __name__ == '__main__':
+    unittest.main()