Greetings, R-Wizards: Earlier this week I requested help with trying to find an extremum subject to a nonlinear constraint. Many thanks to Martin Maechler, Spencer Graves, and Jonathan Baron, who all suggested optim() rather than nlm(), and to Robert Gentleman who suggested using a half-interval search, and special thanks to Patrick Burns and David Khabie-Zeitoune who suggested ways to create an appropriate objective function to use with optim().
While working on the solution I took a closer look at the likelihood profiles and reparameterized to avoid precipitous behavior in the neighborhood of zero. Thus the solution for me was three-fold: 1) Re-parameterize to provide a less-asymmetric likelihood surface. 2) Use box constraints on the parameters to keep the solution-finding under control and thus prevent excursions beyond the domain of parameter feasibility. 3) Define an objective function that had the right objective! ~:-) Thanks to all for your help. Charles Annis, P.E. [EMAIL PROTECTED] phone: 561-352-9699 eFAX: 503-217-5849 http://www.StatisticalEngineering.com ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help
