If you suspect multiple roots, you can try `multiStart' in "BB", which runs `BBsolve' from multiple starting values (which you have to specify).
If you want to convert it to an optimization problem, you can form the sum of squared residuals of the equations and then use `BBoptim'. However, I would not advise that approach when you have a "square" system (i.e. the number of equations is the same as the number of unknowns). The optimization approach is useful (and necessary) for over-determined systems. Best, Ravi. -----Original Message----- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of Werner W. Sent: Friday, August 07, 2009 2:43 AM To: r-help@r-project.org Subject: Re: [R] solving system of equations involving non-linearities Many thanks, BBsolve works like a charm. First I thought I should use the squares of the equations because BBsolve would use some minimization objective function anyway but it actually only works if I don't use the squared equations. I'll check the documentation if I find something about the objective. Thanks for the help, Werner Ravi Varadhan wrote: > > You have two options: > > 1. The `BBsolve' function in the "BB" package to solve this system of 3 > equations. > 2. Try `nleqslv' function in the "nleqslv" package. > > These would work even if the residual is not zero. > > Hope this helps, > Ravi. > -- View this message in context: http://www.nabble.com/solving-system-of-equations-involving-non-linearities- tp24845136p24859703.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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. ______________________________________________ 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.
