optim_share {splitfngr}

Use splitfngr with optim

Description

Use R's optim function but pass in a single function that returns both the function and gradient together in a list. Useful when the function and gradient are expensive to calculate and can be calculated faster together than separate.

Usage

optim_share(par, fngr, ...)

Arguments

par

Initial values for the parameters to be optimized over. Will be passed to optim as par argument.

fngr

A function that returns a list of two elements: the function value and the gradient value.

...

Arguments passed to optim, such as method, lower, upper, control, and hessian.

Value

Results from running optim

Examples

quad_share <- function(x){list(sum(x^4), 4*x^3)}
optim_share(par=c(3, -5), quad_share, method="BFGS")