niche_suitability_cpp: Habitat-suitability kernel (parallel, zero-copy)

In xnicher: Estimates Ecological Niche Models Using Ellipses

Habitat-suitability kernel (parallel, zero-copy)

Description

Evaluates the standardized multivariate-normal density S(x) = \exp(-\frac12 (x-\mu)^\top \Sigma^{-1} (x-\mu)) for each row of a column-major flat environmental buffer. Uses RcppParallel's parallelFor over locations.

Usage

niche_suitability_cpp(
  env_dat_vec,
  env_dat_dims,
  mu,
  L_inv,
  return_log = FALSE,
  num_threads = 0L
)

Arguments

env_dat_vec	Numeric vector. Flat column-major buffer of length n_loc * p; entry for location l variable k sits at index l + n_loc * k.
env_dat_dims	Integer vector c(n_loc, p).
mu	Numeric vector of length p: niche centroid.
L_inv	Numeric matrix p x p: inverse of the lower Cholesky factor of \Sigma. Precomputed R-side once.
return_log	Logical. If FALSE (default) returns suitability in (0, 1]; if TRUE returns \log S(x) \le 0.
num_threads	Integer. 0 (default) leaves RcppParallel's global thread state unchanged.

Value

Numeric vector of length n_loc.

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