def BornAtButNotBefore(week):
table, firsts, others = first.MakeTables(".")
first.ProcessTables(firsts, others)
DropValues(firsts, week)
DropValues(others, week)
firstBabies = Pmf.MakePmfFromList(firsts.lengths, name="First babies")
otherBabies = Pmf.MakePmfFromList(others.lengths, name="Other babies")
return (firstBabies, otherBabies)
return ProbInRange(pmf, lambda week: 38 <= week <= 40)
def ProbLate(pmf):
return ProbInRange(pmf, lambda week: week >= 41)
def FindAndPrintProbs(pmfName, probEarly, probOnTime, probLate):
print '{0} pregnancy length probabilities:\nEarly {1:.2f}%\nOn Time {2:.2f}%\nLate {3:.2f}%\n'.format(
pmfName, probEarly * 100, probOnTime * 100, probLate * 100)
import first
all, firsts, others = first.MakeTables()
first.ProcessTables(all, firsts, others)
import Pmf
pmfFirst = Pmf.MakePmfFromList(firsts.lengths, "First Babies")
firstProbEarly = ProbEarly(pmfFirst)
firstProbOnTime = ProbOnTime(pmfFirst)
firstProbLate = ProbLate(pmfFirst)
FindAndPrintProbs(pmfFirst.name, firstProbEarly, firstProbOnTime,
firstProbLate)
pmfOthers = Pmf.MakePmfFromList(others.lengths, "Other Babies")
otherProbEarly = ProbEarly(pmfOthers)
otherProbOnTime = ProbOnTime(pmfOthers)
otherProbLate = ProbLate(pmfOthers)
FindAndPrintProbs(pmfOthers.name, otherProbEarly, otherProbOnTime,
Pumpkin(591)
]
def Pumpkin():
weights = [p.weight for p in pumpkins]
mu, var = thinkstats.MeanVar(weights)
s = math.sqrt(var)
return (mu, var, s)
print 'mean, variance, standard deviation', Pumpkin()
# ex 2.2
all, firsts, others = first.MakeTables()
first.ProcessTables(firsts, others)
firsts.s = math.sqrt(thinkstats.Var(firsts.lengths, firsts.mu))
others.s = math.sqrt(thinkstats.Var(others.lengths, others.mu))
print 'first babies mean:', firsts.mu, 'standard deviation:', firsts.s
print 'others mean:', others.mu, 'standard deviation:', others.s
print 'mean difference (hours)', (firsts.mu - others.mu) * 7 * 24
print 'spread difference (hours)', (firsts.s - others.s) * 7 * 24
# Distributions
firstsPrgLengthFreqDict = {}
for length in firsts.lengths:
firstsPrgLengthFreqDict[length] = firstsPrgLengthFreqDict.get(length,
0) + 1
def firstBabiesPFM():
all, firsts, others = first.MakeTables()
first.ProcessTables(all, firsts, others)
return Pmf.MakePmfFromList(firsts.lengths, "First Babies")
def otherBabiesPMF():
all, firsts, others = first.MakeTables()
first.ProcessTables(all, firsts, others)
return Pmf.MakePmfFromList(others.lengths, "Other Babies")