wehub-resource-sync
32 lines
702 B
Python
Executable File
32 lines
702 B
Python
Executable File
import numpy as np
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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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from prml.nn.function import Function
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class Log(Function):
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"""
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element-wise natural logarithm of the input
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y = log(x)
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"""
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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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output = np.log(self.x.value)
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if isinstance(self.x, Constant):
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return Constant(output)
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return Tensor(output, function=self)
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def backward(self, delta):
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dx = delta / self.x.value
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self.x.backward(dx)
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def log(x):
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"""
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element-wise natural logarithm of the input
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y = log(x)
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"""
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return Log().forward(x)
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