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SF patch #1191489: Simplify logic in random.py

This commit is contained in:
Raymond Hettinger 2005-04-30 09:02:51 +00:00
parent 53e9a8b9f3
commit 42406e6f27
1 changed files with 10 additions and 9 deletions
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19
Lib/random.py
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@ -345,7 +345,7 @@ class Random(_random.Random):
# Math Software, 3, (1977), pp257-260.
random = self.random
while True:
while 1:
u1 = random()
u2 = 1.0 - random()
z = NV_MAGICCONST*(u1-0.5)/u2
@ -415,7 +415,7 @@ class Random(_random.Random):
b = (a - _sqrt(2.0 * a))/(2.0 * kappa)
r = (1.0 + b * b)/(2.0 * b)
while True:
while 1:
u1 = random()
z = _cos(_pi * u1)
@ -424,7 +424,7 @@ class Random(_random.Random):
u2 = random()
if not (u2 >= c * (2.0 - c) and u2 > c * _exp(1.0 - c)):
if u2 < c * (2.0 - c) or u2 <= c * _exp(1.0 - c):
break
u3 = random()
@ -462,7 +462,7 @@ class Random(_random.Random):
bbb = alpha - LOG4
ccc = alpha + ainv
while True:
while 1:
u1 = random()
if not 1e-7 < u1 < .9999999:
continue
@ -485,18 +485,19 @@ class Random(_random.Random):
# Uses ALGORITHM GS of Statistical Computing - Kennedy & Gentle
while True:
while 1:
u = random()
b = (_e + alpha)/_e
p = b*u
if p <= 1.0:
x = pow(p, 1.0/alpha)
x = p ** (1.0/alpha)
else:
# p > 1
x = -_log((b-p)/alpha)
u1 = random()
if not (((p <= 1.0) and (u1 > _exp(-x))) or
((p > 1) and (u1 > pow(x, alpha - 1.0)))):
if p > 1.0:
if u1 <= x ** (alpha - 1.0):
break
elif u1 <= _exp(-x):
break
return x * beta