From help-request at octave dot org Thu Feb 16 04:12:18 2006 Subject: Re: rand("state") From: Francesco Potorti` To: Mike Miller CC: Bill Denney , Help-Octave List , Paul Kienzle Date: Thu, 16 Feb 2006 11:07:05 +0100 >I just did something else to test how this works. It seems to me that >use of a single 32-bit integer seed works and is fine for many >applications. For all applications, as far as randomness is concerned. >Use of a single integer doesn't change the quality of the random numbers >produced and it is easier to deal with. Yes. >However, the single integer seed limits the number of possible >pseudorandom starting sequences to 2^32. Use of the full 624 32-bit >integers (plus the position integer) allows for all possible 2^19936 >starting sequences. > >If you will be producing many random replicates in a simulation study, it >is better to use the full 625-integer seed so that the probability of any >two replicates being identical is extremely small. > >Do I have this right? Yes. Also, the whole state is necessary if you want to restart the generator from a given point. -- Francesco Potort́ (ricercatore) Voice: +39 050 315 3058 (op.2111) ISTI - Area della ricerca CNR Fax: +39 050 313 8091 via G. Moruzzi 1, I-56124 Pisa Email: Potorti at isti dot cnr dot it Web: http://fly.isti.cnr.it/ Key: fly.isti.cnr.it/public.key ------------------------------------------------------------- Octave is freely available under the terms of the GNU GPL. Octave's home on the web: http://www.octave.org How to fund new projects: http://www.octave.org/funding.html Subscription information: http://www.octave.org/archive.html -------------------------------------------------------------