cppBfgs: Interface to the internal C++ optimization routine "bfgs"
In glmBfp: Bayesian Fractional Polynomials for GLMs

Interface to the internal C++ optimization routine "bfgs"

cppBfgs(
  x0,
  f_,
  min.x = c(-Inf),
  max.x = c(+Inf),
  prec = 1e-05,
  verbose = FALSE
)

`x0`	the start value
`f_`	the target function
`min.x`	minimum bound on x (default `-Inf`)
`max.x`	maximum bound on x (default `+Inf`)
`prec`	precision (default `1e-5`)
`verbose`	be verbose? (not default)

A list with the following elements:

par: the minimum abscissa found by the algorithm
inv.hessian: the inverse Hessian at par
evaluations: list of the function evaluation pairs: args and vals
code: the convergence code. 0 is “OK”, -1 is “lost precision”, and +1 is “change not large enough”