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annotate tvii/sigmoid.py @ 60:38fe99071b11
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author | Jeff Hammel <k0scist@gmail.com> |
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date | Sat, 02 Dec 2017 10:22:25 -0800 |
parents | 38aa9098bf2d |
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16 | 1 """ |
2 sigmoid function: 1/(1 + e^-z) | |
3 """ | |
4 | |
17
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[sigmoid] use numpy + add docstring
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5 import numpy as np |
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[numpy] of course we have to cast everything here too
Jeff Hammel <k0scist@gmail.com>
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6 from .iterable import isiterable |
16 | 7 |
8 def sigmoid(z): | |
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[sigmoid] use numpy + add docstring
Jeff Hammel <k0scist@gmail.com>
parents:
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9 """https://en.wikipedia.org/wiki/Sigmoid_function""" |
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cd43ce453358
[numpy] of course we have to cast everything here too
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parents:
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10 if not isinstance(z, np.ndarray) and isiterable(z): |
cd43ce453358
[numpy] of course we have to cast everything here too
Jeff Hammel <k0scist@gmail.com>
parents:
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diff
changeset
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11 z = np.array(z) |
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bf8bd42f8cd7
[sigmoid] use numpy + add docstring
Jeff Hammel <k0scist@gmail.com>
parents:
16
diff
changeset
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12 return 1./(1. + np.exp(-z)) |
42 | 13 |
14 | |
15 def sigmoidprime(z): | |
16 """"derivative of sigmoid""" | |
17 return sigmoid(z)*(1-sigmoid(z)) |