[R] Retrieving value computed in inner function call

[Gabor Grothendieck]

Check out:

http://finzi.psych.upenn.edu/R/Rhelp02a/archive/83547.html

On 9/12/06, Juan Pablo Lewinger <lewinger at usc.edu> 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
>
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