Re: Re: Creating a Random Function to Select an Irrational

*To*: mathgroup at smc.vnet.net*Subject*: [mg102299] Re: [mg102255] Re: Creating a Random Function to Select an Irrational*From*: Andrzej Kozlowski <akoz at mimuw.edu.pl>*Date*: Tue, 4 Aug 2009 04:30:07 -0400 (EDT)*References*: <200907310957.FAA19545@smc.vnet.net> <200908010801.EAA07130@smc.vnet.net> <200908030945.FAA11901@smc.vnet.net>

On 3 Aug 2009, at 18:45, BenT wrote: > Although I am not > interested in cryptograpy or statistic probabilities for which > "random" numbers are typically used, if not "relied" on, my biggest > concern, that your use of WorkingPrecision partly addresses, is the > prevention of repeating digits within the "random" value which would > imply some sort of "rationality" to the number. Of course you can get any number of repeated digits in a finite expansion of an irrational number. Look for example at the last 6 digits of this: N[Pi, 768] (actually, these last digits should all be 9, as you see by looking at N[Pi, 769]]. If you go long enough you will find a repeating sequence of any length (to get 7 successive repeated digits you need to take a total of 710107 digits of Pi). Thus, there is no advantage in using finite expansions of symbolic irrationals over using RandomReal with high WorkingPrecision. Andrzej Kozlowski

**References**:**Re: Creating a Random Function to Select an Irrational***From:*DrMajorBob <btreat1@austin.rr.com>

**Re: Creating a Random Function to Select an Irrational***From:*BenT <brtubb@pdmusic.org>