Mercurial > hg > tvii
changeset 42:38aa9098bf2d
derivative of sigmoid
| author | Jeff Hammel <k0scist@gmail.com> |
|---|---|
| date | Mon, 04 Sep 2017 14:34:00 -0700 |
| parents | 8c1648921827 |
| children | 2f0caec46e26 |
| files | tests/test_sigmoid.py tvii/sigmoid.py |
| diffstat | 2 files changed, 10 insertions(+), 1 deletions(-) [+] |
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--- a/tests/test_sigmoid.py Mon Sep 04 14:31:25 2017 -0700 +++ b/tests/test_sigmoid.py Mon Sep 04 14:34:00 2017 -0700 @@ -6,7 +6,7 @@ import os import unittest -from tvii.sigmoid import sigmoid +from tvii.sigmoid import sigmoid, sigmoidprime class TestSigmoid(unittest.TestCase): @@ -19,5 +19,9 @@ assert answer[0] == 0.5 assert abs(answer[1] - 0.88079708) < 1e-6 + def test_derivative(self): + + self.assertAlmostEqual(sigmoidprime(0), 0.25) + if __name__ == '__main__': unittest.main()
--- a/tvii/sigmoid.py Mon Sep 04 14:31:25 2017 -0700 +++ b/tvii/sigmoid.py Mon Sep 04 14:34:00 2017 -0700 @@ -10,3 +10,8 @@ if not isinstance(z, np.ndarray) and isiterable(z): z = np.array(z) return 1./(1. + np.exp(-z)) + + +def sigmoidprime(z): + """"derivative of sigmoid""" + return sigmoid(z)*(1-sigmoid(z))