Parakeet/parakeet/utils/scheduler.py

63 lines
1.7 KiB
Python

import math
__all__ = ["SchedulerBase", "Constant", "PieceWise", "StepWise"]
class SchedulerBase(object):
def __call__(self, step):
raise NotImplementedError("You should implement the __call__ method.")
class Constant(SchedulerBase):
def __init__(self, value):
self.value = value
def __call__(self, step):
return self.value
class PieceWise(SchedulerBase):
def __init__(self, anchors):
anchors = list(anchors)
anchors = sorted(anchors, key=lambda x: x[0])
assert anchors[0][0] == 0, "it must start from zero"
self.xs = [item[0] for item in anchors]
self.ys = [item[1] for item in anchors]
self.num_anchors = len(self.xs)
def __call__(self, step):
i = 0
for x in self.xs:
if step >= x:
i += 1
if i == 0:
return self.ys[0]
if i == self.num_anchors:
return self.ys[-1]
k = (self.ys[i] - self.ys[i-1]) / (self.xs[i] - self.xs[i-1])
out = self.ys[i-1] + (step - self.xs[i-1]) * k
return out
class StepWise(SchedulerBase):
def __init__(self, anchors):
anchors = list(anchors)
anchors = sorted(anchors, key=lambda x: x[0])
assert anchors[0][0] == 0, "it must start from zero"
self.xs = [item[0] for item in anchors]
self.ys = [item[1] for item in anchors]
self.num_anchors = len(self.xs)
def __call__(self, step):
i = 0
for x in self.xs:
if step >= x:
i += 1
if i == self.num_anchors:
return self.ys[-1]
if i == 0:
return self.ys[0]
return self.ys[i-1]