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)
#>      bio1WH     bio12WH      bio1WH     bio12WH             
#>   21.397746 1872.493151    1.038323    6.517823    0.000000 
start_theta(example_env_occ_2d, skew = TRUE)
#>      bio1WH     bio12WH      bio1WH     bio12WH                         
#>   21.397746 1872.493151    1.038323    6.517823    0.000000    0.000000 
#>             
#>    0.000000 
start_theta(example_env_occ_2d, skew_t = TRUE)
#>      bio1WH     bio12WH      bio1WH     bio12WH                         
#>   21.397746 1872.493151    1.038323    6.517823    0.000000    0.000000 
#>                         
#>    0.000000    2.302585