Though not obvious at first the posting you pointed me too is very helpful indeed. Thanks a lot Gabor.
Juan Pablo At 08:48 PM 9/12/2006 -0400, Gabor Grothendieck wrote: >Check out: > >http://finzi.psych.upenn.edu/R/Rhelp02a/archive/83547.html > >On 9/12/06, Juan Pablo Lewinger <[EMAIL PROTECTED]> wrote: >>Dear R users, >> >>Consider the following example function: >> >>f = function(a,b) { >> g = function(x) a*x + b >> h = function(x) g(x)^2 + x^2 >> opt = optimize(h,lower = -1, upper = 1) >> x.min = opt$minimum >> h.xmin = opt$objective >> g.xmin = g(x.min) >> return(c(x.min, h.xmin, g.xmin)) >>} >> >>In my real problem the function that plays the role of "g" is costly >>to compute. Now, to minimize "h", "optimize" calls "h" with different >>values of x. In particular, at the end of the optimization, "h" would >>be called with argument x.min, the minimizer of h(x). Therefore, >>buried somewhere, there has to be a call to "g" with argument x=x.min >>which I would like to retrieve in order to avoid the extra call to >>"g" in the line before the return. Can this be done without too much pain? >> >>I'd very much appreciate any help. >> >> >> >>Juan Pablo Lewinger >>Department of Preventive Medicine >>University of Southern California >> >>______________________________________________ >>R-help@stat.math.ethz.ch 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@stat.math.ethz.ch 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.
