27 lines
965 B
Python
27 lines
965 B
Python
from __future__ import print_function
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import numpy as np
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import lib.config as config
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import lib.melbank as melbank
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class ExpFilter:
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"""Simple exponential smoothing filter"""
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def __init__(self, val=0.0, alpha_decay=0.5, alpha_rise=0.5):
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"""Small rise / decay factors = more smoothing"""
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assert 0.0 < alpha_decay < 1.0, 'Invalid decay smoothing factor'
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assert 0.0 < alpha_rise < 1.0, 'Invalid rise smoothing factor'
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self.alpha_decay = alpha_decay
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self.alpha_rise = alpha_rise
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self.value = val
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def update(self, value):
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if isinstance(self.value, (list, np.ndarray, tuple)):
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alpha = value - self.value
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alpha[alpha > 0.0] = self.alpha_rise
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alpha[alpha <= 0.0] = self.alpha_decay
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else:
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alpha = self.alpha_rise if value > self.value else self.alpha_decay
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self.value = alpha * value + (1.0 - alpha) * self.value
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return self.value
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