36 lines
950 B
Python
36 lines
950 B
Python
# Code in this file is copied and adapted from
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# https://github.com/openai/evolution-strategies-starter.
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from __future__ import absolute_import
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from __future__ import division
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from __future__ import print_function
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import numpy as np
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# OPTIMIZERS FOR MINIMIZING OBJECTIVES
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class Optimizer(object):
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def __init__(self, w_policy):
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self.w_policy = w_policy.flatten()
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self.dim = w_policy.size
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self.t = 0
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def update(self, globalg):
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self.t += 1
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step = self._compute_step(globalg)
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ratio = np.linalg.norm(step) / (np.linalg.norm(self.w_policy) + 1e-5)
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return self.w_policy + step, ratio
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def _compute_step(self, globalg):
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raise NotImplementedError
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class SGD(Optimizer):
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def __init__(self, pi, stepsize):
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Optimizer.__init__(self, pi)
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self.stepsize = stepsize
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def _compute_step(self, globalg):
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step = -self.stepsize * globalg
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return step
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