RColorBrewer, dichromat, munsell (>= 0.2), plyr (>= 1.2),
labeling, methods

Variable Metric Nonlinear Function Minimization

Variable metric nonlinear function minimization with bounds constraints.

Conjugate Gradient Minimization of Nonlinear Functions

Conjugate gradient minimization of nonlinear functions
        with box constraints incorporating the Dai/Yuan update. This
        implementation should be used in place of the "CG" algorithm
        of the optim() function.

An object oriented system using object-based, also called
        prototype-based, rather than class-based object oriented ideas.