tedzzx <[EMAIL PROTECTED]> wrote: > > If I want to find out the globle minia, how shoul I change my code?
I sometimes use optim() within a loop, with random starting values for each iteration of the loop. You can save the objective function value each time and pick the best solution. Last time I did that, I ran it 100 times. That procedure does not guarantee finding the global minimum. However, it does make it *more likely* to find the global minmum *within the range of your starting values*. Often, I make a boxplot of the various results. If they don't show a strong mode, there is a data or model problem that needs to be addressed. For example, the solution may be poorly defined by the data, or the model may be specified with confounded parameters. -- Mike Prager, NOAA, Beaufort, NC * Opinions expressed are personal and not represented otherwise. * Any use of tradenames does not constitute a NOAA endorsement. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
