Re: ISING model

*To*: mathgroup at smc.vnet.net*Subject*: [mg23629] Re: ISING model*From*: "Atul Sharma" <atulksharma at yahoo.com>*Date*: Wed, 24 May 2000 02:16:32 -0400 (EDT)*Organization*: McGill University*References*: <8eg7v5$hgg@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

I missed this post when it first appeared, as I was out of town. Apologies if the response is too late to be of any use. Richard Gaylord and Paul Wellin discuss the Ising spin model in their book: Computer Simulations with Mathematica: Explorations in Complex Physical and Biological Systems (Telos/Springer Verlaag) Chapter 6 deals implements the 'standard' Ising model with the Metropolis algorithm. Chapter 10 implements the Q2R version of the model. The authors describe the difference as " The Q2R model is a CA version of the Ising model which was discussed in Chapter 6. The two models differ in several significant ways. Q2R uses a microcanonical ensemble approach while the Metropolis Ising model uses a canonical ensemble approach. In Q2R, all of the spins are flipped simultaneously while in the Metropolis model only one randomly selected spin is flipped at a time. The spin-flipping decision is deterministic in Q2R while it is probabilistic in the Metropolis model.Both versions of the Ising model give many comparable results (though it should be pointed out that the Q2R program is not exactly equivalent to Metropolis Ising program because the CA is not ergodic) and we will not be concerned with those results here." In keeping with the practical orientation of the book, both chapters are a bit short on theory, but they do have working implementations of the two approaches. Wolfgang Kinzel and Georg Reents (Physics by Computer: Programming Physical Problems Using Mathematica and C ) have a more detailed discussion of the theory. If I recall correctly, the C routine for the Metropolis algorithm runs externally under MathLink, which confers a significant speed gain. The book is in my office, so my recall is sketchy. If you would like more detail as to what it contains, feel free to write me off-list. Bonne chance Atul ----------------------------------------------------------- Atul Sharma MD, FRCP(C) Pediatric Nephrologist, McGill University/Montreal Children's Hospital Raphael Suire wrote in message <8eg7v5$hgg at smc.vnet.net>... > >Dear list, > >Help, i'am looking for a source for an ISING model > >Is anybody one know if there exist a source code for this kind of > interacting particle system ???? > >many thanks, > >Raphael Suire > > > >********************************************************************** >Raphael Suire0 >CREREG - UMR CNRS 6585 > 0 > >Faculte de Sciences Economiques >7, place >Hoche, >CS86514 >35065 Rennes-France >raphael.suire at univ-rennes1.fr >********************************************************************* >