thin_by_dist: Thin points dataset based on geographic distance

In tidysdm: Species Distribution Models with Tidymodels

Thin points dataset based on geographic distance

Description

This function thins a dataset so that only observations that have a distance from each other greater than "dist_min" are retained.

Usage

thin_by_dist(
  data,
  dist_min,
  coords = NULL,
  dist_method = c("great_circle", "euclidean")
)

Arguments

data	An sf::sf data frame, or a data frame with coordinate variables. These can be defined in coords, unless they have standard names (see details below).
dist_min	Minimum distance between points (in units appropriate for the projection, or meters for lonlat data).
coords	A vector of length two giving the names of the "x" and "y" coordinates, as found in data. If left to NULL, the function will try to guess the columns based on standard names c("x", "y"), c("X","Y"), c("longitude", "latitude"), or c("lon", "lat")
dist_method	method to compute distance, either "euclidean" or "great_circle". Defaults to "great_circle", which is more accurate but takes slightly longer.

Details

Distances are measured in the appropriate units for the projection used. In case of raw latitude and longitude (e.g. as provided in a data.frame), the crs is set to WGS84, and units are set to meters.

This function is a modified version of the algorithm in spThin, adapted to work on sf objects.

Value

An object of class sf::sf or data.frame, the same as "data".

tidysdm documentation built on April 3, 2025, 9:56 p.m.