dist_pres_vs_bg {tidysdm}

Distance between the distribution of climate values for presences vs background

Description

For each environmental variable, this function computes the density functions of presences and absences and returns (1-overlap), which is a measure of the distance between the two distributions. Variables with a high distance are good candidates for SDMs, as species occurrences are confined to a subset of the available background.

Usage

dist_pres_vs_bg(.data, .col)

Arguments

.data

a data.frame (or derived object, such as tibble, or sf) with values for the bioclimate variables for presences and background

.col

the column containing the presences; it assumes presences to be the first level of this factor

Value

a name vector of distances

Examples

# This should be updated to use a dataset from tidysdm
data("bradypus", package = "maxnet")
bradypus_tb <- tibble::as_tibble(bradypus) %>%
  dplyr::mutate(presence = relevel(
    factor(
      dplyr::case_match(presence, 1 ~ "presence", 0 ~ "absence")
    ),
    ref = "presence"
  )) %>%
  select(-ecoreg)

bradypus_tb %>% dist_pres_vs_bg(presence)