start_theta: Starting values for niche model on math scale

In xnicher: Estimates Ecological Niche Models Using Ellipses

Starting values for niche model on math scale

Description

Starting values for niche model on math scale

Usage

start_theta(env_occ, skew = FALSE, skew_t = FALSE)

Arguments

env_occ	Data frame with environmental values at presence points.
skew	Logical. If TRUE, append p zeros for the skew parameters (alpha_1, ..., alpha_p). The Gaussian-only start (skew = FALSE, the default) is used for "presence_only", "weighted", and "ip_weighted"; the skew start is used for "skew_normal" and "skew_normal_weighted".
skew_t	Logical. If TRUE, append log(10) for the skew-t degrees-of-freedom parameter log_r after the alpha block (used for "skew_t" and "skew_t_weighted"). Implies skew = TRUE.

Value

Numeric vector of starting values for 'theta'.

Examples

start_theta(example_env_occ_2d)
start_theta(example_env_occ_2d, skew = TRUE)
start_theta(example_env_occ_2d, skew_t = TRUE)

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