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[Jython-checkins] SF.net SVN: jython:[5360] trunk/jython
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From: <zy...@us...> - 2008-10-06 03:13:20
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Revision: 5360
http://jython.svn.sourceforge.net/jython/?rev=5360&view=rev
Author: zyasoft
Date: 2008-10-06 03:12:34 +0000 (Mon, 06 Oct 2008)
Log Message:
-----------
Removed older version of random.py in favor of CPythonLib's; added
_random.getrandbits (in PyRandom); modified test_random so that it
doesn't test implementation specific aspects of the random generator,
since we actually use java.util.Random, not the Mersenne Twister.
Modified Paths:
--------------
trunk/jython/Lib/test/test_random.py
trunk/jython/src/org/python/modules/random/PyRandom.java
Removed Paths:
-------------
trunk/jython/Lib/random.py
Deleted: trunk/jython/Lib/random.py
===================================================================
--- trunk/jython/Lib/random.py 2008-10-06 03:02:29 UTC (rev 5359)
+++ trunk/jython/Lib/random.py 2008-10-06 03:12:34 UTC (rev 5360)
@@ -1,880 +0,0 @@
-"""Random variable generators.
-
- integers
- --------
- uniform within range
-
- sequences
- ---------
- pick random element
- pick random sample
- generate random permutation
-
- distributions on the real line:
- ------------------------------
- uniform
- normal (Gaussian)
- lognormal
- negative exponential
- gamma
- beta
- pareto
- Weibull
-
- distributions on the circle (angles 0 to 2pi)
- ---------------------------------------------
- circular uniform
- von Mises
-
-General notes on the underlying Mersenne Twister core generator:
-
-* The period is 2**19937-1.
-* It is one of the most extensively tested generators in existence
-* Without a direct way to compute N steps forward, the
- semantics of jumpahead(n) are weakened to simply jump
- to another distant state and rely on the large period
- to avoid overlapping sequences.
-* The random() method is implemented in C, executes in
- a single Python step, and is, therefore, threadsafe.
-
-"""
-import time
-from types import BuiltinMethodType as _BuiltinMethodType
-from math import log as _log, exp as _exp, pi as _pi, e as _e
-from math import sqrt as _sqrt, acos as _acos, cos as _cos, sin as _sin
-from math import floor as _floor
-from os import urandom as _urandom
-from binascii import hexlify as _hexlify
-
-
-__all__ = ["Random","seed","random","uniform","randint","choice","sample",
- "randrange","shuffle","normalvariate","lognormvariate",
- "cunifvariate","expovariate","vonmisesvariate","gammavariate",
- "stdgamma","gauss","betavariate","paretovariate","weibullvariate",
- "getstate","setstate","jumpahead", "WichmannHill"]
-
-NV_MAGICCONST = 4 * _exp(-0.5)/_sqrt(2.0)
-TWOPI = 2.0*_pi
-LOG4 = _log(4.0)
-SG_MAGICCONST = 1.0 + _log(4.5)
-BPF = 53 # Number of bits in a float
-RECIP_BPF = 2**-BPF
-
-# Translated by Guido van Rossum from C source provided by
-# Adrian Baddeley. Adapted by Raymond Hettinger for use with
-# the Mersenne Twister core generator.
-
-import _random
-
-class Random(_random.Random):
- """Random number generator base class used by bound module functions.
-
- Used to instantiate instances of Random to get generators that don't
- share state. Especially useful for multi-threaded programs, creating
- a different instance of Random for each thread, and using the jumpahead()
- method to ensure that the generated sequences seen by each thread don't
- overlap.
-
- Class Random can also be subclassed if you want to use a different basic
- generator of your own devising: in that case, override the following
- methods: random(), seed(), getstate(), setstate() and jumpahead().
-
- """
-
- VERSION = 2 # used by getstate/setstate
-
- def __init__(self, x=None):
- """Initialize an instance.
-
- Optional argument x controls seeding, as for Random.seed().
- """
-
- self.seed(x)
- self.gauss_next = None
-
- def seed(self, a=None):
- """Initialize internal state from hashable object.
-
- None or no argument seeds from current time.
-
- If a is not None or an int or long, hash(a) is used instead.
- """
-
- if a is None:
- a = long(time.time() * 256) # use fractional seconds
- super(Random, self).seed(a)
- self.gauss_next = None
-
- def getstate(self):
- """Return internal state; can be passed to setstate() later."""
- return self.VERSION, super(Random, self).getstate(), self.gauss_next
-
- def setstate(self, state):
- """Restore internal state from object returned by getstate()."""
- version = state[0]
- if version == 2:
- version, internalstate, self.gauss_next = state
- super(Random, self).setstate(internalstate)
- else:
- raise ValueError("state with version %s passed to "
- "Random.setstate() of version %s" %
- (version, self.VERSION))
-
-## ---- Methods below this point do not need to be overridden when
-## ---- subclassing for the purpose of using a different core generator.
-
-## -------------------- pickle support -------------------
-
- def __getstate__(self): # for pickle
- return self.getstate()
-
- def __setstate__(self, state): # for pickle
- self.setstate(state)
-
- def __reduce__(self):
- return self.__class__, (), self.getstate()
-
-## -------------------- integer methods -------------------
-
- def randrange(self, start, stop=None, step=1, int=int, default=None,
- maxwidth=1L<<BPF, _BuiltinMethod=_BuiltinMethodType):
- """Choose a random item from range(start, stop[, step]).
-
- This fixes the problem with randint() which includes the
- endpoint; in Python this is usually not what you want.
- Do not supply the 'int', 'default', and 'maxwidth' arguments.
- """
-
- # This code is a bit messy to make it fast for the
- # common case while still doing adequate error checking.
- istart = int(start)
- if istart != start:
- raise ValueError, "non-integer arg 1 for randrange()"
- if stop is default:
- if istart > 0:
- if istart >= maxwidth and type(self.random) is _BuiltinMethod:
- return self._randbelow(istart)
- return int(self.random() * istart)
- raise ValueError, "empty range for randrange()"
-
- # stop argument supplied.
- istop = int(stop)
- if istop != stop:
- raise ValueError, "non-integer stop for randrange()"
- width = istop - istart
- if step == 1 and width > 0:
- # Note that
- # int(istart + self.random()*(istop - istart))
- # instead would be incorrect. For example, consider istart
- # = -2 and istop = 0. Then the guts would be in
- # -2.0 to 0.0 exclusive on both ends (ignoring that random()
- # might return 0.0), and because int() truncates toward 0, the
- # final result would be -1 or 0 (instead of -2 or -1).
- # istart + int(self.random()*(istop - istart))
- # would also be incorrect, for a subtler reason: the RHS
- # can return a long, and then randrange() would also return
- # a long, but we're supposed to return an int (for backward
- # compatibility).
- if width >= maxwidth and type(self.random) is _BuiltinMethod:
- return int(istart + self._randbelow(width))
- return int(istart + int(self.random()*width))
- if step == 1:
- raise ValueError, "empty range for randrange()"
-
- # Non-unit step argument supplied.
- istep = int(step)
- if istep != step:
- raise ValueError, "non-integer step for randrange()"
- if istep > 0:
- n = (width + istep - 1) / istep
- elif istep < 0:
- n = (width + istep + 1) / istep
- else:
- raise ValueError, "zero step for randrange()"
-
- if n <= 0:
- raise ValueError, "empty range for randrange()"
-
- if n >= maxwidth and type(self.random) is _BuiltinMethod:
- return istart + self._randbelow(n)
- return istart + istep*int(self.random() * n)
-
- def randint(self, a, b):
- """Return random integer in range [a, b], including both end points.
- """
-
- return self.randrange(a, b+1)
-
- def _randbelow(self, n, bpf=BPF, maxwidth=1L<<BPF,
- long=long, _log=_log, int=int):
- """Return a random int in the range [0,n)
-
- Handles the case where n has more bits than returned
- by a single call to the underlying generator.
- """
-
- # k is a sometimes over but never under estimate of the bits in n
- k = int(1.00001 + _log(n-1, 2)) # 2**k > n-1 >= 2**(k-2)
-
- random = self.random
- r = n
- while r >= n:
- # In Py2.4, this section becomes: r = self.getrandbits(k)
- r = long(random() * maxwidth)
- bits = bpf
- while bits < k:
- r = (r << bpf) | (long(random() * maxwidth))
- bits += bpf
- r >>= (bits - k)
- return r
-
-## -------------------- sequence methods -------------------
-
- def choice(self, seq):
- """Choose a random element from a non-empty sequence."""
- return seq[int(self.random() * len(seq))]
-
- def shuffle(self, x, random=None, int=int):
- """x, random=random.random -> shuffle list x in place; return None.
-
- Optional arg random is a 0-argument function returning a random
- float in [0.0, 1.0); by default, the standard random.random.
-
- Note that for even rather small len(x), the total number of
- permutations of x is larger than the period of most random number
- generators; this implies that "most" permutations of a long
- sequence can never be generated.
- """
-
- if random is None:
- random = self.random
- for i in xrange(len(x)-1, 0, -1):
- # pick an element in x[:i+1] with which to exchange x[i]
- j = int(random() * (i+1))
- x[i], x[j] = x[j], x[i]
-
- def sample(self, population, k):
- """Chooses k unique random elements from a population sequence.
-
- Returns a new list containing elements from the population while
- leaving the original population unchanged. The resulting list is
- in selection order so that all sub-slices will also be valid random
- samples. This allows raffle winners (the sample) to be partitioned
- into grand prize and second place winners (the subslices).
-
- Members of the population need not be hashable or unique. If the
- population contains repeats, then each occurrence is a possible
- selection in the sample.
-
- To choose a sample in a range of integers, use xrange as an argument.
- This is especially fast and space efficient for sampling from a
- large population: sample(xrange(10000000), 60)
- """
-
- # Sampling without replacement entails tracking either potential
- # selections (the pool) in a list or previous selections in a
- # dictionary.
-
- # When the number of selections is small compared to the population,
- # then tracking selections is efficient, requiring only a small
- # dictionary and an occasional reselection. For a larger number of
- # selections, the pool tracking method is preferred since the list takes
- # less space than the dictionary and it doesn't suffer from frequent
- # reselections.
-
- n = len(population)
- if not 0 <= k <= n:
- raise ValueError, "sample larger than population"
- random = self.random
- _int = int
- result = [None] * k
- if n < 6 * k: # if n len list takes less space than a k len dict
- pool = list(population)
- for i in xrange(k): # invariant: non-selected at [0,n-i)
- j = _int(random() * (n-i))
- result[i] = pool[j]
- pool[j] = pool[n-i-1] # move non-selected item into vacancy
- else:
- try:
- n > 0 and (population[0], population[n//2], population[n-1])
- except (TypeError, KeyError): # handle sets and dictionaries
- population = tuple(population)
- selected = {}
- for i in xrange(k):
- j = _int(random() * n)
- while j in selected:
- j = _int(random() * n)
- result[i] = selected[j] = population[j]
- return result
-
-## -------------------- real-valued distributions -------------------
-
-## -------------------- uniform distribution -------------------
-
- def uniform(self, a, b):
- """Get a random number in the range [a, b)."""
- return a + (b-a) * self.random()
-
-## -------------------- normal distribution --------------------
-
- def normalvariate(self, mu, sigma):
- """Normal distribution.
-
- mu is the mean, and sigma is the standard deviation.
-
- """
- # mu = mean, sigma = standard deviation
-
- # Uses Kinderman and Monahan method. Reference: Kinderman,
- # A.J. and Monahan, J.F., "Computer generation of random
- # variables using the ratio of uniform deviates", ACM Trans
- # Math Software, 3, (1977), pp257-260.
-
- random = self.random
- while True:
- u1 = random()
- u2 = 1.0 - random()
- z = NV_MAGICCONST*(u1-0.5)/u2
- zz = z*z/4.0
- if zz <= -_log(u2):
- break
- return mu + z*sigma
-
-## -------------------- lognormal distribution --------------------
-
- def lognormvariate(self, mu, sigma):
- """Log normal distribution.
-
- If you take the natural logarithm of this distribution, you'll get a
- normal distribution with mean mu and standard deviation sigma.
- mu can have any value, and sigma must be greater than zero.
-
- """
- return _exp(self.normalvariate(mu, sigma))
-
-## -------------------- circular uniform --------------------
-
- def cunifvariate(self, mean, arc):
- """Circular uniform distribution.
-
- mean is the mean angle, and arc is the range of the distribution,
- centered around the mean angle. Both values must be expressed in
- radians. Returned values range between mean - arc/2 and
- mean + arc/2 and are normalized to between 0 and pi.
-
- Deprecated in version 2.3. Use:
- (mean + arc * (Random.random() - 0.5)) % Math.pi
-
- """
- # mean: mean angle (in radians between 0 and pi)
- # arc: range of distribution (in radians between 0 and pi)
- import warnings
- warnings.warn("The cunifvariate function is deprecated; Use (mean "
- "+ arc * (Random.random() - 0.5)) % Math.pi instead.",
- DeprecationWarning, 2)
-
- return (mean + arc * (self.random() - 0.5)) % _pi
-
-## -------------------- exponential distribution --------------------
-
- def expovariate(self, lambd):
- """Exponential distribution.
-
- lambd is 1.0 divided by the desired mean. (The parameter would be
- called "lambda", but that is a reserved word in Python.) Returned
- values range from 0 to positive infinity.
-
- """
- # lambd: rate lambd = 1/mean
- # ('lambda' is a Python reserved word)
-
- random = self.random
- u = random()
- while u <= 1e-7:
- u = random()
- return -_log(u)/lambd
-
-## -------------------- von Mises distribution --------------------
-
- def vonmisesvariate(self, mu, kappa):
- """Circular data distribution.
-
- mu is the mean angle, expressed in radians between 0 and 2*pi, and
- kappa is the concentration parameter, which must be greater than or
- equal to zero. If kappa is equal to zero, this distribution reduces
- to a uniform random angle over the range 0 to 2*pi.
-
- """
- # mu: mean angle (in radians between 0 and 2*pi)
- # kappa: concentration parameter kappa (>= 0)
- # if kappa = 0 generate uniform random angle
-
- # Based upon an algorithm published in: Fisher, N.I.,
- # "Statistical Analysis of Circular Data", Cambridge
- # University Press, 1993.
-
- # Thanks to Magnus Kessler for a correction to the
- # implementation of step 4.
-
- random = self.random
- if kappa <= 1e-6:
- return TWOPI * random()
-
- a = 1.0 + _sqrt(1.0 + 4.0 * kappa * kappa)
- b = (a - _sqrt(2.0 * a))/(2.0 * kappa)
- r = (1.0 + b * b)/(2.0 * b)
-
- while True:
- u1 = random()
-
- z = _cos(_pi * u1)
- f = (1.0 + r * z)/(r + z)
- c = kappa * (r - f)
-
- u2 = random()
-
- if not (u2 >= c * (2.0 - c) and u2 > c * _exp(1.0 - c)):
- break
-
- u3 = random()
- if u3 > 0.5:
- theta = (mu % TWOPI) + _acos(f)
- else:
- theta = (mu % TWOPI) - _acos(f)
-
- return theta
-
-## -------------------- gamma distribution --------------------
-
- def gammavariate(self, alpha, beta):
- """Gamma distribution. Not the gamma function!
-
- Conditions on the parameters are alpha > 0 and beta > 0.
-
- """
-
- # alpha > 0, beta > 0, mean is alpha*beta, variance is alpha*beta**2
-
- # Warning: a few older sources define the gamma distribution in terms
- # of alpha > -1.0
- if alpha <= 0.0 or beta <= 0.0:
- raise ValueError, 'gammavariate: alpha and beta must be > 0.0'
-
- random = self.random
- if alpha > 1.0:
-
- # Uses R.C.H. Cheng, "The generation of Gamma
- # variables with non-integral shape parameters",
- # Applied Statistics, (1977), 26, No. 1, p71-74
-
- ainv = _sqrt(2.0 * alpha - 1.0)
- bbb = alpha - LOG4
- ccc = alpha + ainv
-
- while True:
- u1 = random()
- if not 1e-7 < u1 < .9999999:
- continue
- u2 = 1.0 - random()
- v = _log(u1/(1.0-u1))/ainv
- x = alpha*_exp(v)
- z = u1*u1*u2
- r = bbb+ccc*v-x
- if r + SG_MAGICCONST - 4.5*z >= 0.0 or r >= _log(z):
- return x * beta
-
- elif alpha == 1.0:
- # expovariate(1)
- u = random()
- while u <= 1e-7:
- u = random()
- return -_log(u) * beta
-
- else: # alpha is between 0 and 1 (exclusive)
-
- # Uses ALGORITHM GS of Statistical Computing - Kennedy & Gentle
-
- while True:
- u = random()
- b = (_e + alpha)/_e
- p = b*u
- if p <= 1.0:
- x = pow(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)))):
- break
- return x * beta
-
-
- def stdgamma(self, alpha, ainv, bbb, ccc):
- # This method was (and shall remain) undocumented.
- # This method is deprecated
- # for the following reasons:
- # 1. Returns same as .gammavariate(alpha, 1.0)
- # 2. Requires caller to provide 3 extra arguments
- # that are functions of alpha anyway
- # 3. Can't be used for alpha < 0.5
-
- # ainv = sqrt(2 * alpha - 1)
- # bbb = alpha - log(4)
- # ccc = alpha + ainv
- import warnings
- warnings.warn("The stdgamma function is deprecated; "
- "use gammavariate() instead.",
- DeprecationWarning, 2)
- return self.gammavariate(alpha, 1.0)
-
-
-
-## -------------------- Gauss (faster alternative) --------------------
-
- def gauss(self, mu, sigma):
- """Gaussian distribution.
-
- mu is the mean, and sigma is the standard deviation. This is
- slightly faster than the normalvariate() function.
-
- Not thread-safe without a lock around calls.
-
- """
-
- # When x and y are two variables from [0, 1), uniformly
- # distributed, then
- #
- # cos(2*pi*x)*sqrt(-2*log(1-y))
- # sin(2*pi*x)*sqrt(-2*log(1-y))
- #
- # are two *independent* variables with normal distribution
- # (mu = 0, sigma = 1).
- # (Lambert Meertens)
- # (corrected version; bug discovered by Mike Miller, fixed by LM)
-
- # Multithreading note: When two threads call this function
- # simultaneously, it is possible that they will receive the
- # same return value. The window is very small though. To
- # avoid this, you have to use a lock around all calls. (I
- # didn't want to slow this down in the serial case by using a
- # lock here.)
-
- random = self.random
- z = self.gauss_next
- self.gauss_next = None
- if z is None:
- x2pi = random() * TWOPI
- g2rad = _sqrt(-2.0 * _log(1.0 - random()))
- z = _cos(x2pi) * g2rad
- self.gauss_next = _sin(x2pi) * g2rad
-
- return mu + z*sigma
-
-## -------------------- beta --------------------
-## See
-## http://sourceforge.net/bugs/?func=detailbug&bug_id=130030&group_id=5470
-## for Ivan Frohne's insightful analysis of why the original implementation:
-##
-## def betavariate(self, alpha, beta):
-## # Discrete Event Simulation in C, pp 87-88.
-##
-## y = self.expovariate(alpha)
-## z = self.expovariate(1.0/beta)
-## return z/(y+z)
-##
-## was dead wrong, and how it probably got that way.
-
- def betavariate(self, alpha, beta):
- """Beta distribution.
-
- Conditions on the parameters are alpha > -1 and beta} > -1.
- Returned values range between 0 and 1.
-
- """
-
- # This version due to Janne Sinkkonen, and matches all the std
- # texts (e.g., Knuth Vol 2 Ed 3 pg 134 "the beta distribution").
- y = self.gammavariate(alpha, 1.)
- if y == 0:
- return 0.0
- else:
- return y / (y + self.gammavariate(beta, 1.))
-
-## -------------------- Pareto --------------------
-
- def paretovariate(self, alpha):
- """Pareto distribution. alpha is the shape parameter."""
- # Jain, pg. 495
-
- u = 1.0 - self.random()
- return 1.0 / pow(u, 1.0/alpha)
-
-## -------------------- Weibull --------------------
-
- def weibullvariate(self, alpha, beta):
- """Weibull distribution.
-
- alpha is the scale parameter and beta is the shape parameter.
-
- """
- # Jain, pg. 499; bug fix courtesy Bill Arms
-
- u = 1.0 - self.random()
- return alpha * pow(-_log(u), 1.0/beta)
-
-## -------------------- Wichmann-Hill -------------------
-
-class WichmannHill(Random):
-
- VERSION = 1 # used by getstate/setstate
-
- def seed(self, a=None):
- """Initialize internal state from hashable object.
-
- None or no argument seeds from current time.
-
- If a is not None or an int or long, hash(a) is used instead.
-
- If a is an int or long, a is used directly. Distinct values between
- 0 and 27814431486575L inclusive are guaranteed to yield distinct
- internal states (this guarantee is specific to the default
- Wichmann-Hill generator).
- """
-
- if a is None:
- # Initialize from current time
- import time
- a = long(time.time() * 256)
-
- if not isinstance(a, (int, long)):
- a = hash(a)
-
- a, x = divmod(a, 30268)
- a, y = divmod(a, 30306)
- a, z = divmod(a, 30322)
- self._seed = int(x)+1, int(y)+1, int(z)+1
-
- self.gauss_next = None
-
- def random(self):
- """Get the next random number in the range [0.0, 1.0)."""
-
- # Wichman-Hill random number generator.
- #
- # Wichmann, B. A. & Hill, I. D. (1982)
- # Algorithm AS 183:
- # An efficient and portable pseudo-random number generator
- # Applied Statistics 31 (1982) 188-190
- #
- # see also:
- # Correction to Algorithm AS 183
- # Applied Statistics 33 (1984) 123
- #
- # McLeod, A. I. (1985)
- # A remark on Algorithm AS 183
- # Applied Statistics 34 (1985),198-200
-
- # This part is thread-unsafe:
- # BEGIN CRITICAL SECTION
- x, y, z = self._seed
- x = (171 * x) % 30269
- y = (172 * y) % 30307
- z = (170 * z) % 30323
- self._seed = x, y, z
- # END CRITICAL SECTION
-
- # Note: on a platform using IEEE-754 double arithmetic, this can
- # never return 0.0 (asserted by Tim; proof too long for a comment).
- return (x/30269.0 + y/30307.0 + z/30323.0) % 1.0
-
- def getstate(self):
- """Return internal state; can be passed to setstate() later."""
- return self.VERSION, self._seed, self.gauss_next
-
- def setstate(self, state):
- """Restore internal state from object returned by getstate()."""
- version = state[0]
- if version == 1:
- version, self._seed, self.gauss_next = state
- else:
- raise ValueError("state with version %s passed to "
- "Random.setstate() of version %s" %
- (version, self.VERSION))
-
- def jumpahead(self, n):
- """Act as if n calls to random() were made, but quickly.
-
- n is an int, greater than or equal to 0.
-
- Example use: If you have 2 threads and know that each will
- consume no more than a million random numbers, create two Random
- objects r1 and r2, then do
- r2.setstate(r1.getstate())
- r2.jumpahead(1000000)
- Then r1 and r2 will use guaranteed-disjoint segments of the full
- period.
- """
-
- if not n >= 0:
- raise ValueError("n must be >= 0")
- x, y, z = self._seed
- x = int(x * pow(171, n, 30269)) % 30269
- y = int(y * pow(172, n, 30307)) % 30307
- z = int(z * pow(170, n, 30323)) % 30323
- self._seed = x, y, z
-
- def __whseed(self, x=0, y=0, z=0):
- """Set the Wichmann-Hill seed from (x, y, z).
-
- These must be integers in the range [0, 256).
- """
-
- if not type(x) == type(y) == type(z) == int:
- raise TypeError('seeds must be integers')
- if not (0 <= x < 256 and 0 <= y < 256 and 0 <= z < 256):
- raise ValueError('seeds must be in range(0, 256)')
- if 0 == x == y == z:
- # Initialize from current time
- import time
- t = long(time.time() * 256)
- t = int((t&0xffffff) ^ (t>>24))
- t, x = divmod(t, 256)
- t, y = divmod(t, 256)
- t, z = divmod(t, 256)
- # Zero is a poor seed, so substitute 1
- self._seed = (x or 1, y or 1, z or 1)
-
- self.gauss_next = None
-
- def whseed(self, a=None):
- """Seed from hashable object's hash code.
-
- None or no argument seeds from current time. It is not guaranteed
- that objects with distinct hash codes lead to distinct internal
- states.
-
- This is obsolete, provided for compatibility with the seed routine
- used prior to Python 2.1. Use the .seed() method instead.
- """
-
- if a is None:
- self.__whseed()
- return
- a = hash(a)
- a, x = divmod(a, 256)
- a, y = divmod(a, 256)
- a, z = divmod(a, 256)
- x = (x + a) % 256 or 1
- y = (y + a) % 256 or 1
- z = (z + a) % 256 or 1
- self.__whseed(x, y, z)
-## --------------- Operating System Random Source ------------------
-
-class SystemRandom(Random):
- """Alternate random number generator using sources provided
- by the operating system (such as /dev/urandom on Unix or
- CryptGenRandom on Windows).
-
- Not available on all systems (see os.urandom() for details).
- """
-
- def random(self):
- """Get the next random number in the range [0.0, 1.0)."""
- return (long(_hexlify(_urandom(7)), 16) >> 3) * RECIP_BPF
-
- def getrandbits(self, k):
- """getrandbits(k) -> x. Generates a long int with k random bits."""
- if k <= 0:
- raise ValueError('number of bits must be greater than zero')
- if k != int(k):
- raise TypeError('number of bits should be an integer')
- bytes = (k + 7) // 8 # bits / 8 and rounded up
- x = long(_hexlify(_urandom(bytes)), 16)
- return x >> (bytes * 8 - k) # trim excess bits
-
- def _stub(self, *args, **kwds):
- "Stub method. Not used for a system random number generator."
- return None
- seed = jumpahead = _stub
-
- def _notimplemented(self, *args, **kwds):
- "Method should not be called for a system random number generator."
- raise NotImplementedError('System entropy source does not have state.')
- getstate = setstate = _notimplemented
-
-## -------------------- test program --------------------
-
-def _test_generator(n, funccall):
- import time
- print n, 'times', funccall
- code = compile(funccall, funccall, 'eval')
- total = 0.0
- sqsum = 0.0
- smallest = 1e10
- largest = -1e10
- t0 = time.time()
- for i in range(n):
- x = eval(code)
- total += x
- sqsum = sqsum + x*x
- smallest = min(x, smallest)
- largest = max(x, largest)
- t1 = time.time()
- print round(t1-t0, 3), 'sec,',
- avg = total/n
- stddev = _sqrt(sqsum/n - avg*avg)
- print 'avg %g, stddev %g, min %g, max %g' % \
- (avg, stddev, smallest, largest)
-
-
-def _test(N=2000):
- _test_generator(N, 'random()')
- _test_generator(N, 'normalvariate(0.0, 1.0)')
- _test_generator(N, 'lognormvariate(0.0, 1.0)')
- _test_generator(N, 'cunifvariate(0.0, 1.0)')
- _test_generator(N, 'vonmisesvariate(0.0, 1.0)')
- _test_generator(N, 'gammavariate(0.01, 1.0)')
- _test_generator(N, 'gammavariate(0.1, 1.0)')
- _test_generator(N, 'gammavariate(0.1, 2.0)')
- _test_generator(N, 'gammavariate(0.5, 1.0)')
- _test_generator(N, 'gammavariate(0.9, 1.0)')
- _test_generator(N, 'gammavariate(1.0, 1.0)')
- _test_generator(N, 'gammavariate(2.0, 1.0)')
- _test_generator(N, 'gammavariate(20.0, 1.0)')
- _test_generator(N, 'gammavariate(200.0, 1.0)')
- _test_generator(N, 'gauss(0.0, 1.0)')
- _test_generator(N, 'betavariate(3.0, 3.0)')
-
-# Create one instance, seeded from current time, and export its methods
-# as module-level functions. The functions share state across all uses
-#(both in the user's code and in the Python libraries), but that's fine
-# for most programs and is easier for the casual user than making them
-# instantiate their own Random() instance.
-
-_inst = Random()
-seed = _inst.seed
-random = _inst.random
-uniform = _inst.uniform
-randint = _inst.randint
-choice = _inst.choice
-randrange = _inst.randrange
-sample = _inst.sample
-shuffle = _inst.shuffle
-normalvariate = _inst.normalvariate
-lognormvariate = _inst.lognormvariate
-cunifvariate = _inst.cunifvariate
-expovariate = _inst.expovariate
-vonmisesvariate = _inst.vonmisesvariate
-gammavariate = _inst.gammavariate
-stdgamma = _inst.stdgamma
-gauss = _inst.gauss
-betavariate = _inst.betavariate
-paretovariate = _inst.paretovariate
-weibullvariate = _inst.weibullvariate
-getstate = _inst.getstate
-setstate = _inst.setstate
-jumpahead = _inst.jumpahead
-
-if __name__ == '__main__':
- _test()
Modified: trunk/jython/Lib/test/test_random.py
===================================================================
--- trunk/jython/Lib/test/test_random.py 2008-10-06 03:02:29 UTC (rev 5359)
+++ trunk/jython/Lib/test/test_random.py 2008-10-06 03:12:34 UTC (rev 5360)
@@ -530,6 +530,12 @@
TestDistributions,
TestModule]
+ if test_support.is_jython:
+ del MersenneTwister_TestBasicOps.test_genrandbits
+ del MersenneTwister_TestBasicOps.test_referenceImplementation
+ del MersenneTwister_TestBasicOps.test_setstate_middle_arg
+ del MersenneTwister_TestBasicOps.test_strong_reference_implementation
+
try:
random.SystemRandom().random()
except NotImplementedError:
Modified: trunk/jython/src/org/python/modules/random/PyRandom.java
===================================================================
--- trunk/jython/src/org/python/modules/random/PyRandom.java 2008-10-06 03:02:29 UTC (rev 5359)
+++ trunk/jython/src/org/python/modules/random/PyRandom.java 2008-10-06 03:12:34 UTC (rev 5360)
@@ -5,6 +5,7 @@
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
+import java.math.BigInteger;
import java.util.Random;
import org.python.core.Py;
@@ -45,7 +46,9 @@
seed = new PyLong(System.currentTimeMillis());
}
if (seed instanceof PyLong) {
- this.javaRandom.setSeed(((PyLong)seed).asLong(0));
+ PyLong max = new PyLong(Long.MAX_VALUE);
+ PyLong seed_modulus = (PyLong)(seed.__mod__(max));
+ this.javaRandom.setSeed(((PyLong)seed_modulus).asLong(0));
} else if (seed instanceof PyInteger) {
this.javaRandom.setSeed(((PyInteger)seed).getValue());
} else {
@@ -137,4 +140,9 @@
double ret=(a*67108864.0+b)*(1.0/9007199254740992.0);
return new PyFloat(ret);
}
+
+ @ExposedMethod
+ public PyLong Random_getrandbits(int k) {
+ return new PyLong(new BigInteger(k, javaRandom));
+ }
}
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