Thank you for the reply. In my code(C++), I use try/catch to catch exceptions, and as you say COBYLA does not print anything. I debugged the code to determine the reason for the exception and found "cobyla: rounding errors are becoming damaging."
In one case, exception occurs after 30 evaluations. So far if I use another initial value error does not occur so I don't think my code has a bug. > >> I'm using cobyla. >> Sometimes NLopt halts with exception error >> "cobyla: rounding errors are becoming damaging." >> without normal negative return code. >> >> This happens when I first run minimization and use the results as >> initial values for the next minimization which includes almost the >> same data >> as the first one. >> >> What is the reason of this error? >> How can I avoid this error? > >Something very strange is happening, because COBYLA should never print >anything unless its internal variable iprint is > 0, but iprint is set >to 0 and as far as I can tell is never changed by the code. > >I'm guessing that you have a memory-overrun bug in your code (e.g. you >are writing past the end of an array) and hence are overwriting >arbitrary memory and causing strange errors. Try using a memory >debugger like valgrind. > >--SGJ > >_______________________________________________ >NLopt-discuss mailing list >[email protected] >http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/nlopt-discuss _______________________________________________ NLopt-discuss mailing list [email protected] http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/nlopt-discuss
