Re: Multiple independent random number streams cannot be implemented.
- To: mathgroup at smc.vnet.net
- Subject: [mg130205] Re: Multiple independent random number streams cannot be implemented.
- From: Vince Virgilio <blueschi at gmail.com>
- Date: Tue, 19 Mar 2013 01:51:52 -0400 (EDT)
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On Tuesday, March 19, 2013 12:05:01 AM UTC-4, David Bailey wrote: > On 18/03/2013 09:34, Vince Virgilio wrote: > > > On Sunday, March 17, 2013 7:48:21 PM UTC-4, David Bailey wrote: > > > ... > > >> Unfortunately, the documentation at 9.0 deprecates the use of > > >> > > >> $RandomState - stating that it is superseded by BlockRandom - but > > >> > > >> clearly $RandomState can solve problems which BlockRandom cannot. > > > > > > Agreed. So use Random`GetRandomState[] . > > > > > > Vince > > > > > I don't understand your point, Random`GetRandomState is not documented > > at all, and $RandomState is stated to be superseded by BlockRandom! > > > > My point is that $RandomState should not be superseded by a function > > that is less useful! > > > > People like to use functions that are documented and not superseded, > > because that gives them confidence that they will continue to exist in > > future versions! > > > > David Bailey > > http://www.dbaileyconsultancy.co.uk OK, not documented. But Random`GetRandomState has worked for years for me (if I recall the duration correctly). I think in versions 6-8. It's in 9 too. I forgot that Random`GetRandomState[] was not documented. And I forgot how I learned about it. Probably from WRI TS, but can't find the email. Obviously there's a gap in the design of Mathematica's PRNG system, which you indicate. BlockRandom does not completely supersede $RandomState. Pity. I probably stumbled across this long ago, asked TS about it, and got GetRandomState back in a response. I don't think the gap can be otherwise overcome, unless I'm missing something in the documentation (tutorial/RandomNumber Generation, around section "Defining Your Own Generator"). WRI should document and baseline it in the next release (major, minor, or point), hm? Vince
- References:
- Multiple independent random number streams cannot be implemented.
- From: Roger Wilson <rogerhw999@gmail.com>
- Multiple independent random number streams cannot be implemented.