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#!/usr/bin/env python |
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# -*- coding: utf-8 -*- |
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import theano.tensor as T |
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class Cost(object): |
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def get(self): |
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return NotImplementedError() |
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class CrossEntropyCost(Cost): |
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def __init__(self, result_tensor, index_tensor): |
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self.result_tensor = result_tensor |
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self.index_tensor = index_tensor |
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def get(self): |
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return -T.mean(T.log(self.result_tensor)[T.arange(self.index_tensor.shape[0]), self.index_tensor]) |
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class RegressionCost(Cost): |
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def __init__(self, result_tensor, target_tensor): |
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self.result_tensor = result_tensor |
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self.target_tensor = target_tensor |
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def get(self): |
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err = self.result_tensor - self.target_tensor |
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return T.mean((err * err).sum(axis=self.target_tensor.ndim - 1)) / 2 |
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class AutoEncoderCost(Cost): |
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def __init__(self, result_tensor, target_tensor): |
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self.result_tensor = result_tensor |
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self.target_tensor = target_tensor |
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def get(self): |
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return T.sum((self.result_tensor - self.target_tensor)**2) |
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class ErrorRateCost(Cost): |
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def __init__(self, result_tensor, index_tensor): |
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self.result_tensor = result_tensor |
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self.index_tensor = index_tensor |
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def get(self): |
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return 100 * T.mean(T.neq(T.argmax(self.result_tensor, axis=1), self.index_tensor)) |