generate_pa_buffer_out: Generate Pseudo-Absences Using Buffer-Out Strategy

In glossa: User-Friendly 'shiny' App for Bayesian Species Distribution Models

Generate Pseudo-Absences Using Buffer-Out Strategy

Description

This function generates pseudo-absences outside a buffer around presence points but within the convex hull of those points. This prevents spatial overlap while preserving geographic realism.

Usage

generate_pa_buffer_out(
  presences,
  raster_stack,
  predictor_variables,
  coords = c("decimalLongitude", "decimalLatitude"),
  pa_buffer_distance = 0.5,
  ratio = 1,
  attempts = 100,
  seed = NULL
)

Arguments

presences	Data frame containing presence points.
raster_stack	'SpatRaster' object containing covariate data.
predictor_variables	Character vector of the predictor variables selected for this species.
coords	Character vector specifying the column names for latitude and longitude. Defaults to 'c("decimalLongitude", "decimalLatitude")'.
pa_buffer_distance	Numeric; buffer radius in degrees around each presence. Default is 0.5.
ratio	Ratio of pseudo-absences to presences (default 1 = balanced).
attempts	Integer specifying the number of attempts to generate exact pseudo-absences. Defaults to 100.
seed	Optional seed for reproducibility.

Value

A data frame of pseudo-absences with coordinates, timestamp, 'pa = 0', and covariate values.

glossa documentation built on June 8, 2025, 1:20 p.m.