optimize_niche_xptr: Optimize niche model using a compiled XPtr backend

In xnicher: Estimates Ecological Niche Models Using Ellipses

Optimize niche model using a compiled XPtr backend

Description

Runs ucminfcpp::ucminf_xptr() over a compiled C++ objective function created by create_niche_obj_ptr(). Supports single-start and multi-start optimization. Ensures that all starting vectors are numeric doubles and finite.

Usage

optimize_niche_xptr(
  start = NULL,
  xptr,
  control = ucminfcpp::ucminf_control(grad = "central", gradstep = c(1e-06, 1e-08),
    maxeval = 200),
  multi_start = FALSE
)

Arguments

start	Numeric vector (single start) or list of numeric vectors (multi-start).
xptr	External pointer created by create_niche_obj_ptr().
control	List of control parameters for ucminfcpp::ucminf_control().
multi_start	Logical; TRUE if multiple starts are supplied.

Value

A list with:

• par — best parameter vector

• value — negative log-likelihood

• conv — convergence code

• all_results — (multi-start only) table of all runs

Examples

## optimize_niche() uses optimize_niche_xptr() internally;
## call it directly for full control over each optimization run:
fit <- optimize_niche(
  env_occ    = example_env_occ_3d,
  env_m      = example_env_m_3d,
  num_starts = 3L,
  likelihood = "ip_weighted"
)
fit$best$value

xnicher documentation built on Sept. 15, 2026, 5:08 p.m.