measurements.py

   1 import math
   2
   3 from number import Number
   4
   5 def avg(l):
   6     assert len(l)
   7     return sum(l) / float(len(l))
   8
   9 class MethodAnalyzer:
  10     def __init__(self):
  11         self.method_data = {}
  12         self.method_avg_sdsq = {}
  13
  14     def addMeasurement(self, m):
  15         assert m.method
  16         l = self.method_data.get(m.method, [])
  17         l.append( m.computeStats() )
  18         self.method_data[m.method] = l
  19
  20     def computeStats(self, verbose=False):
  21         for method, l in self.method_data.iteritems():
  22             avg_sdsq = avg( [ t[2] for t in l ] )
  23             min_sdsq = min( t[2] for t in l )
  24             max_sdsq = max( t[2] for t in l )
  25
  26             self.method_avg_sdsq[method] = avg_sdsq
  27             if verbose:
  28                 print method
  29                 print "min =", min_sdsq
  30                 print "avg =", avg_sdsq
  31                 print "max =", max_sdsq
  32
  33 class M:
  34     def __init__(self, name, ms, method=None, units=None, precise=False):
  35         if units == None:
  36             units = {'m':1}
  37
  38         if precise:
  39             assert len(ms) == 1
  40
  41         self.name = name
  42         self.ms = map(float, ms)
  43         #self.ms = ms
  44         self.method = method
  45         self.units = units
  46         self.precise = precise
  47
  48     def computeStats(self):
  49         n = len(self.ms)
  50         mean = avg(self.ms)
  51         # delime takhle kvuli nevychylenymu odhadu
  52         sdsq = sum((x - mean)**2 for x in self.ms) / ( (n - 1) if n > 1 else 1 )
  53
  54         return (n, mean, sdsq)
  55
  56     def toNumber(self, method_resolution=None, method_analyzer=None):
  57         if self.precise:
  58             return Number(self.ms[0], units=self.units, string=self.name)
  59
  60         n, mean, sdsq = self.computeStats()
  61         if self.method:
  62             if method_analyzer:
  63                 mavg = method_analyzer.method_avg_sdsq[self.method]
  64                 if sdsq < mavg:
  65                     sdsq = mavg
  66
  67             # the more measurements, the better
  68             sdsq /= n
  69
  70             if method_resolution:
  71                 # add the resolution of the method
  72                 sdsq += method_resolution[self.method] ** 2
  73
  74         return Number(mean, sdsq=sdsq, units=self.units, string=self.name)