def __init__(self):
"""Initializes the cache.
joint: map from (age, bucket) to frequency
sequences: map from bucket to a list of sequences
initial_rdt: sequence of (V0, rdt) pairs
"""
self.joint = thinkbayes.Joint()
self.sequences = {}
self.initial_rdt = []
def makeOneCauseMI(p=0.5, q=0.5):
px=prob.MakePmfFromDict({"H":p, "L":1.0-p})
joint = prob.Joint()
for v1, p1 in px.Items():
if v1 =="H":
joint.Set((v1, "H"), p1*q)
joint.Set((v1, "L"), p1*q)
else:
joint.Set((v1, "H"), 0.0)
joint.Set((v1, "L"), p1*1.0)
py=joint.Marginal(1)
return px, py, joint
def GetDistAgeSize(self, size_thresh=MAXSIZE):
"""Gets the joint distribution of age and size.
Map from (age, log size in cm) to log freq
Returns: new Pmf object
"""
joint = thinkbayes.Joint()
for val, freq in self.joint.Items():
age, bucket = val
cm = BucketToCm(bucket)
if cm > size_thresh:
continue
log_cm = math.log10(cm)
joint.Set((age, log_cm), math.log(freq) * 10)
return joint