wehub-resource-sync
27 lines
639 B
Python
Executable File
27 lines
639 B
Python
Executable File
import scipy.special as sp
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from prml.nn.function import Function
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from prml.nn.tensor.constant import Constant
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from prml.nn.tensor.tensor import Tensor
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class Gamma(Function):
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def forward(self, x):
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x = self._convert2tensor(x)
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self.x = x
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self.output = sp.gamma(x.value)
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if isinstance(x, Constant):
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return Constant(self.output)
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return Tensor(self.output, function=self)
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def backward(self, delta):
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dx = delta * self.output * sp.digamma(self.x.value)
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self.x.backward(dx)
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def gamma(x):
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"""
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element-wise gamma function
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"""
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return Gamma().forward(x)
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