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import logging |
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logger = logging.getLogger(__name__) |
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class ConstIterations: |
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"""Stopping Criterion: After certain iterations |
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Args: |
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num_iters (:obj:`int`): Number of iterations |
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Attributes: |
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num_iters (:obj:`int`): Number of iterations |
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cur_iter (:obj:`int`): Current number of iterations |
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""" |
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def __init__(self, num_iters): |
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self.num_iters = num_iters |
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self.cur_iter = 0 |
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def reset(self): |
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"""Reset internal iteration counter |
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""" |
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self.cur_iter = 0 |
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def continue_learning(self): |
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"""Determine whether learning should continue |
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If so, return True, otherwise, return False. |
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""" |
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if self.cur_iter < self.num_iters: |
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self.cur_iter += 1 |
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return True |
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else: |
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return False |
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class MonitorBased: |
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"""Stop training based on the return of a monitoring function. |
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If the monitoring result keep improving within past n_steps, keep learning. |
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Otherwise, stop. |
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If the monitoring result is the best at the moment, call the parameter save |
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function. |
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Once it is done, the parameters saved last is the training results. |
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Args: |
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n_steps (:obj:`int`): The amount of steps to look for improvement |
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monitor_fn: Parameter monitor function. |
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monitor_fn_args (:obj:`tuple`): Argument tuple (arg1, arg2, ...) for monitor function. |
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save_fn: Parameter save function. |
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save_fn_args (:obj:`tuple`): Argument tuple (arg1, arg2, ...) for save function. |
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Attributes: |
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n_steps (:obj:`int`): The amount of steps to look for improvement |
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monitor_fn: Parameter monitor function. |
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monitor_fn_args (:obj:`tuple`): Argument tuple (arg1, arg2, ...) for monitor function. |
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save_fn: Parameter save function. |
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save_fn_args (:obj:`tuple`): Argument tuple (arg1, arg2, ...) for save function. |
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step_count (:obj:`int`): Number of steps that the parameter monitored is worse than the best value. |
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best_value: Best value seen so far. |
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""" |
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def __init__(self, n_steps, monitor_fn, monitor_fn_args, save_fn, save_fn_args): |
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self.n_steps = n_steps |
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self.monitor_fn = monitor_fn |
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self.monitor_fn_args = monitor_fn_args |
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self.save_fn = save_fn |
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self.save_fn_args = save_fn_args |
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self.step_count = 0 |
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self.best_value = None |
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def reset(self): |
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"""Reset internal step count |
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""" |
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self.step_count = 0 |
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self.best_value = None |
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def continue_learning(self): |
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"""Determine whether learning should continue |
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If so, return True, otherwise, return False. |
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""" |
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param = self.monitor_fn(*self.monitor_fn_args) |
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if self.best_value is None: |
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self.best_value = param |
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self.save_fn(*self.save_fn_args) |
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if param > self.best_value: |
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self.step_count = 0 |
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self.best_value = param |
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self.save_fn(*self.save_fn_args) |
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logger.info('New Best: %g' % self.best_value) |
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else: |
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self.step_count += 1 |
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if self.step_count > self.n_steps: |
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return False |
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return True |
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