[R-pkg-devel] query about package design

[ProfJCNash]

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.

Best,

JN