Danf: some random notes, quotes, & code

2015-01-07T20:44:19Z

some random notes, quotes, & code

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''some random notes, quotes, & code''

[https://en.wikipedia.org/wiki/Randomness Wikipedia]
<pre>
Although randomness had often been viewed as an obstacle and a nuisance for many
centuries, in the twentieth century computer scientists began to realize that
the deliberate introduction of randomness into computations can be an effective
tool for designing better algorithms.
</pre>
* [https://en.wikipedia.org/wiki/Algorithmically_random_sequence Algorithmic Randomness]
* [https://en.wikipedia.org/wiki/Algorithmic_information_theory Algorithmic Information Theory]
<pre>
Unlike classical information theory, algorithmic information theory gives formal,
rigorous definitions of a random string and a random infinite sequence that do not
depend on physical or philosophical intuitions about nondeterminism or likelihood.
</pre>

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[https://docs.python.org/2/library/random.html Python]
<pre>
Python uses the Mersenne Twister as the core generator. It produces
53-bit precision floats and has a period of 2**19937-1 [...] However,
being completely deterministic, it is not suitable for all purposes,
and is completely unsuitable for cryptographic purposes.
</pre>
(Mersenne Twister replaced Wichmann-Hill as default generator in Python 2.3)
<pre>
The random module also provides the SystemRandom class which uses the
system function os.urandom() to generate random numbers from sources
provided by the operating system.
</pre>

example:
<pre>
import random

foo = random.getrandbits(1024) # mersenne twister, returns arbitrarily long integer
print(bin(foo))

altrand = random.SystemRandom() # not available on all systems, assumes entropy source

bar = altrand.getrandbits(1024)
print(bin(bar))
</pre>

[[Category:Math]]

Randomness - Revision history

Danf: some random notes, quotes, & code