[R-pkg-devel] query about package design

[Hadley Wickham]

On Fri, Jul 10, 2015 at 12:50 PM, ProfJCNash <profjcnash at gmail.com> wrote:
> I have a general question about appropriate design for a fairly
> complicated package, as I am redesigning and rebuilding the optimx
> package. It will get a new name as it appears that the calls will change
> in order to accommodate new functionality. I plan to make it
> fairly easy to add new optimization (function minimization) tools.
>
> The query is whether to use an environment to hold all the common
> objects (functions, scaled functions, gradients, scaled gradients,
> hessians, scaled hessians, parameters, scaled parameters, program
> controls, algorithm tuning parameters, constraints, fixed parametes,
> some function value history, etc.) The alternative is a set of very
> long calls, especially when the function needing a quantity may be a
> couple of layers below the routine that creates or sets the values.
>
> The negative side is that the functions are not portable outside the
> package, so would not be exported.
>
> Before I dig into the heavy clay of code that this will need, I thought
> I should ask if there are issues I might be missing, as the local
> environment -- essentially "global" variables within the perimeter of
> the package -- would make the code a lot cleaner, and may offer some
> useful efficiencies in computation.

If you want to store the same set of things for many optimisers, you
might want to consider using reference classes or R6.

Hadley

-- 
http://had.co.nz/