Jiao: there is nothing to fix, indeterminism is not bad. :) Cross-linking is always a good idea Jerome. It would be nice to add the links. OTOH, indeterminism is a topic in itself, not strictly related to multithreading. What people sometimes don't realize, is that the one-thread result is not better than multithread. j>1 reveals the indeterminism, j=1 hides it, but it is still indeterminate in both cases.
Reordering interactions in a one thread simulation would give different results, and I don't think Yade is magicaly choosing a "best" ordering. Consequently, j=1 should be seen like running a random number generator with always the same seed, while j>1 initializes the seed with the computer's clock (i.e. "randomly"). Bruno On 10/05/12 11:28, Jérôme Duriez wrote: > Hello Liqing > > - please think to https://answers.launchpad.net/yade/+addquestion to > ask question ;-) > > - second, give a look to > https://yade-dem.org/doc/formulation.html#result-indeterminism > concerning your problem. > > This was several times discussed on the lists, but I understand you > were not aware of this, I had myself difficulties to find this link. > Perhaps would it be particularly useful to put this link in > https://www.yade-dem.org/doc/prog.html#parallel-execution or > https://www.yade-dem.org/doc/user.html#controlling-parallel-compuation > for example ? > > Jerome > > Le 10/05/2012 11:08, Liqing Jiao a écrit : >> Dear all, >> >> When the same script runs on the same version of yade, but one is >> single core, another one is multi-cores, the results are different. I >> use yade trunk version, which is recommended by Anton. It's good. But >> when I run the same script, the result is different. You can try the >> concrete uniax.py, which is in examples folder, you will see the >> different lines printed out on the screen. And I tried my model both >> using parallel and non parallel running, the results are also >> different. Thank you for your attention. Could you please reply me if >> you know how to fix it? Thank you in advance. >> >> Cheers, Liqing >> >> >> >> >> _______________________________________________ >> Mailing list: https://launchpad.net/~yade-users >> Post to : [email protected] >> Unsubscribe : https://launchpad.net/~yade-users >> More help : https://help.launchpad.net/ListHelp > -- _______________ Bruno Chareyre Associate Professor ENSE³ - Grenoble INP 11, rue des Mathématiques BP 46 38402 St Martin d'Hères, France Tél : +33 4 56 52 86 21 Fax : +33 4 76 82 70 43 ________________ _______________________________________________ Mailing list: https://launchpad.net/~yade-users Post to : [email protected] Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
