src/gpodder/corestats.py

   1
   2 #
   3 #  corestats.py (COREy STATS)
   4 #  Copyright (c) 2006-2007, Corey Goldberg (corey@goldb.org)
   5 #  http://www.goldb.org/corestats.html
   6 #
   7 #    statistical calculation class
   8 #    for processing numeric sequences
   9 #
  10 #  license: GNU LGPL
  11 #
  12 #  This library is free software; you can redistribute it and/or
  13 #  modify it under the terms of the GNU Lesser General Public
  14 #  License as published by the Free Software Foundation; either
  15 #  version 2.1 of the License, or (at your option) any later version.
  16 #
  17 # Slightly modified for use in gPodder
  18 #
  19
  20 class Stats(object):
  21     def __init__(self, sequence):
  22         # sequence of numbers we will process
  23         # convert all items to floats for numerical processing
  24         self.sequence = [float(item) for item in sequence]
  25
  26     def sum(self):
  27         if len(self.sequence) < 1:
  28             return None
  29         else:
  30             return sum(self.sequence)
  31
  32     def count(self):
  33         return len(self.sequence)
  34
  35     def min(self):
  36         if len(self.sequence) < 1:
  37             return None
  38         else:
  39             return min(self.sequence)
  40
  41     def max(self):
  42         if len(self.sequence) < 1:
  43             return None
  44         else:
  45             return max(self.sequence)
  46
  47     def avg(self):
  48         if len(self.sequence) < 1:
  49             return None
  50         else:
  51             return sum(self.sequence) / len(self.sequence)
  52
  53     def median(self):
  54         if len(self.sequence) < 1:
  55             return None
  56         else:
  57             self.sequence.sort()
  58             return self.sequence[len(self.sequence) // 2]
  59
  60     def stdev(self):
  61         if len(self.sequence) < 1:
  62             return None
  63         else:
  64             avg = self.avg()
  65             sdsq = sum([(i - avg) ** 2 for i in self.sequence])
  66             stdev = (sdsq / (len(self.sequence) - 1)) ** .5
  67             return stdev
  68
  69     def percentile(self, percentile):
  70         if len(self.sequence) < 1:
  71             value = None
  72         elif percentile >= 100:
  73             raise ValueError('percentile must be < 100')
  74         else:
  75             element_idx = int(len(self.sequence) * (percentile / 100.0))
  76             self.sequence.sort()
  77             value = self.sequence[element_idx]
  78         return value
  79