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init

master
Stephen McQuay 6 years ago
commit
d649a2b114
  1. 1
      ostat/__init__.py
  2. 55
      ostat/ostat.py
  3. 16
      setup.py

1
ostat/__init__.py

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from .ostat import OnlineStat

55
ostat/ostat.py

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import math
class OnlineStat(object):
def __init__(self):
self.n = 0.0
self.min = float('inf')
self.max = float('-inf')
self.old_m = 0.0
self.old_s = 0.0
self.new_m = 0.0
self.new_s = 0.0
def push(self, x):
self.n += 1
if x < self.min:
self.min = x
if x > self.max:
self.max = x
self.new_m = self.old_m + (x - self.old_m) / self.n
self.new_s = self.old_s + (x - self.old_m) * (x - self.new_m)
self.old_m = self.new_m
self.old_s = self.new_s
@property
def mean(self):
return self.new_m if self.n > 0 else 0.0
@property
def variance(self):
return self.new_s / (self.n) if self.n > 1 else 0.0
@property
def stddev(self):
return math.sqrt(self.variance)
def __unicode__(self):
return u'{min} {mean} {max} {stddev}'.format(
min=self.min,
mean=self.mean,
max=self.max,
stddev=self.stddev,
)
def __str__(self):
return u'{}'.format(self).encode('utf8')
def __repr__(self):
return u'<OnlineStat {}>'.format(self)

16
setup.py

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from setuptools import setup
setup(
name='ostat',
version='0.1',
description=(
'efficient, accurate, and stable calculation of online '
'statistical quantities.'
),
url='https://s.mcquay.me/sm/py-ostat/',
author='Stephen McQuay',
author_email='stephen@mcquay.me',
license='MIT',
packages=['ostat'],
zip_safe=False,
)
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