Hi Arvind, The problem is likely with your code. If your function is using an uninitialized variable, then the function output will change depending on what happened to be in memory at the time the function was called.
Best, Grey > On Dec 15, 2016, at 8:05 AM, Iyer, Arvind S <a.i...@imperial.ac.uk> wrote: > > Hi, > I am a new user of the nl-opt library. Thanks to the developers for such a > wonderful collection. > > I recently observed that NLOPT_LN_NEWUOA based optimisation > yields different results (sometimes drastically different) on multiple > invocation over > the same problem starting from the same guess. > > The problem itself can have multiple local minima and its understandable that > this algorithm clings to the nearest one. However, I did not expect different > results for the same problem with same starting point. > > This seems like the presence of a random number initialization of some > parameter. > I am myself not aware of the details of the algorithm and its implementation. > > Can someone confirm that this is indeed so? And perhaps a way to seed the > random number if this is the case. > > Thanks again > > Arvind > From: NLopt-discuss <nlopt-discuss-boun...@ab-initio.mit.edu> on behalf of > nlopt-discuss-requ...@ab-initio.mit.edu<nlopt-discuss-requ...@ab-initio.mit.edu> > Sent: 15 December 2016 12:58:11 > To: Iyer, Arvind S > Subject: Welcome to the "NLopt-discuss" mailing list > > Welcome to the NLopt-discuss@ab-initio.mit.edu mailing list! > > To post to this list, send your message to: > > nlopt-discuss@ab-initio.mit.edu > > General information about the mailing list is at: > > http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/nlopt-discuss > > If you ever want to unsubscribe or change your options (eg, switch to > or from digest mode, change your password, etc.), visit your > subscription page at: > > > http://ab-initio.mit.edu/cgi-bin/mailman/options/nlopt-discuss/a.iyer%40imperial.ac.uk > > > You can also make such adjustments via email by sending a message to: > > nlopt-discuss-requ...@ab-initio.mit.edu > > with the word `help' in the subject or body (don't include the > quotes), and you will get back a message with instructions. > > You must know your password to change your options (including changing > the password, itself) or to unsubscribe without confirmation. It is: > > Bujji@123 > > Normally, Mailman will remind you of your ab-initio.mit.edu mailing > list passwords once every month, although you can disable this if you > prefer. This reminder will also include instructions on how to > unsubscribe or change your account options. There is also a button on > your options page that will email your current password to you. > _______________________________________________ > NLopt-discuss mailing list > NLopt-discuss@ab-initio.mit.edu > http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/nlopt-discuss _______________________________________________ NLopt-discuss mailing list NLopt-discuss@ab-initio.mit.edu http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/nlopt-discuss
