From: couturie Date: Wed, 18 Apr 2012 05:46:45 +0000 (+0200) Subject: suite X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/turing4complexity.git/commitdiff_plain/19eb8563c27a0b70b252e940814dd379ff434074 suite --- diff --git a/turing4complexity.tex b/turing4complexity.tex index bbc2e69..2146039 100644 --- a/turing4complexity.tex +++ b/turing4complexity.tex @@ -19,7 +19,7 @@ blabalbabla In their paper, they introduced a method to compute the complexity of D(n). With D(4), 5 970 768 960 machines halt. There are 1832 different strings. -\section{PRNG preserve distribution of short strings} +\section{Property: a PRNG must preserve the distribution of short strings} In this section, we propose to measure the quality of a PRNG by considering that a good PRNG must preserve the distribution of short strings. More precisely, the @@ -27,6 +27,16 @@ pseudo-random numbers obtained by a PRNG can form the states of the Rado's original Busy Beaver. Then, machines obtained by such a construction can be executed and if the PRNG is good, machines should generate the same strings with the same distribution than the theoretical Busy Beaver (with all the enumeration -of states). +of states). In practice, PRNGs will not generate all the strings with exactly +the same probabilities. Nevertheless, the distance between the theoretical +probabibilities and the obtained probabilities with a PRNG is a good indication +of the quality of the PRNG. + +In the following we report our experiments. Let $S_i$ be the string number $i$ +obtained by the busy beaver, $S(n)$ is the set of strings of $D(n)$. With $D(4)$ +there are 1832 strings, so $|S(4)|=1832$. $P_t(S_i)$ is the theoretical +probability of the string $S_i$ and $P_{PRNG}(S_i)$ is the probability of the +string $S_i$ obtained with the execution of a given PRNG. Let For $D(n)$, the +number of strings is \end{document}